RULES FOR CLASSIFICATION Ships Edition July 2020 Amended January 2021 Part 2 Materials and welding Chapter 4 Fabrication and testing The content of this service document is the subject of intellectual property rights reserved by DNV GL AS ("DNV GL"). The user accepts that it is prohibited by anyone else but DNV GL and/or its licensees to offer and/or perform classification, certification and/or verification services, including the issuance of certificates and/or declarations of conformity, wholly or partly, on the basis of and/or pursuant to this document whether free of charge or chargeable, without DNV GL's prior written consent. DNV GL is not responsible for the consequences arising from any use of this document by others. The electronic PDF version of this document, available at the DNV GL website dnvgl.com, is the official, binding version. DNV GL AS
Transcript
RULES FOR CLASSIFICATION
Ships
Edition July 2020Amended January 2021
Part 2 Materials and welding
Chapter 4 Fabrication and testing
The content of this service document is the subject of intellectual property rights reserved by DNV GL AS ("DNV GL"). The useraccepts that it is prohibited by anyone else but DNV GL and/or its licensees to offer and/or perform classification, certificationand/or verification services, including the issuance of certificates and/or declarations of conformity, wholly or partly, on thebasis of and/or pursuant to this document whether free of charge or chargeable, without DNV GL's prior written consent.DNV GL is not responsible for the consequences arising from any use of this document by others.
The electronic PDF version of this document, available at the DNV GL website dnvgl.com, is the official, binding version.
DNV GL AS
FOREWORD
DNV GL rules for classification contain procedural and technical requirements related to obtainingand retaining a class certificate. The rules represent all requirements adopted by the Society asbasis for classification.
This service document has been prepared based on available knowledge, technology and/or information at the time of issuance of thisdocument. The use of this document by others than DNV GL is at the user's sole risk. Unless otherwise stated in an applicable contract,or following from mandatory law, the liability of DNV GL AS, its parent companies and subsidiaries as well as their officers, directors andemployees ("DNV GL") for proved loss or damage arising from or in connection with any act or omission of DNV GL, whether in contract or intort (including negligence), shall be limited to direct losses and under any circumstance be limited to 300,000 USD.
CHANGES – CURRENT
This document supersedes the July 2019 edition of DNVGL-RU-SHIP Pt.2 Ch.4.The numbering and/or title of items containing changes is highlighted in red.
Amendments January 2021, entering into force 1 July 2021
Topic Reference Description
Updated external references Sec.1 Table 2 Added or updated references to:
— ASME BPVC IX— ASME BPVC V— EN ISO 9712:2012— ISO 3452:2013— ISO 11666:2018— ISO 10675:2016— ISO 23277:2015— ISO 15626:2018— ISO 19285:2017.
Updated terminology anddefinitions
Sec.1 Table 3 Probability of detection (POD) indicates the probability that atesting technique will detect a given flaw.
Sec.7 [1.5.3] Added that preparation and cleaning shall be in accordance withapproved NDT procedures.
Sec.7 [1.5.4] Added final NDT after heat treatment.
Sec.7 [1.5.5] Completion of NDT after delay time. Added specific delay timetable.
Sec.7 [1.5.6] Added delay time requirement for steels regardless of yieldstrength grade.
Sec.7 [1.5.7] Added the possibility of relaxation of delay time period.
Sec.7 [2.1.3] Added that NDT reports shall be in line with the approved NDTprocedures.
Sec.7 [6.1.2] andSec.7 [6.1.3]
Former subsection [6.1.1] updated and split into subsections[6.1.2] and [6.1.3].
IACS UR W33 Non-destructivetesting of ship hull steel welds
Sec.7 [6.1.4] Added correlation of quality level references for RT onaluminium.
Sec.7 [2.1.1] Added note that qualification of advanced NDT shall followspecial procedure prior to approval.
Sec.7 [2.1.3] Added that the content of the report shall be in accordance withthe procedure.
Sec.7 [2.7] and Sec.7[2.7.1]
Added that for advanced NDT the technique and procedurequalification shall be in accordance with DNVGL-CG-0051.
Sec.7 [6.1.5] Added acceptance level for TOFD.
IACS UR W34 Advanced non-destructive testing of materialsand welds
Sec.7 [6.1.6] Added acceptance level of PAUT.
Part 2 Chapter 4 Changes - current
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 3Fabrication and testing
DNV GL AS
Topic Reference Description
Sec.7 [6.2.1] Added subsection for indications exceeding the applicableacceptance criteria.
Changes July 2020, entering into force 1 January 2021
Topic Reference Description
WWA for permanentunderwater wet-welding andthe repairs
If permanent underwater wet-welding shall be approved forrepairs, the welding workshop shall be DNV GL approved as ingeneral required for important components.
WWA for chemical or gas cargopiping systems
Sec.1 Table 1 WWA requirement for chemical or gas cargo piping systemsincluded similar to that for class I and II piping systems.
Sec.1 Table 2 Align relevant standards for personnel qualification andcertification with IACS UR W35.
Sec.1 Table 4 The supervisor shall be certified by an accredited certificationbody - no in-house certification or appointment by themanufacturer.
Sec.1 Table 8 Added survey, inspection and testing requirements for non-destructive testing.
Sec.2 [1.2.2] List of documentation requirements to be fulfilled by NDTsuppliers.
Sec.2 [2.1.2] New subsection. List of requirements for the documentationextent of the quality management system to be fulfilled by NDTsuppliers.
Sec.7 [1.1.1] Added quality aspects regarding competence and internalquality control for NDT suppliers.
Sec.7 Table 1 Added NDT personnel certification for operator(s) andsupervisor(s) and supervisor tasks.
Sec.7 [2.1.1] Requirement of written procedures to be approved by level 3personnel.
Sec.7 [3.1] Added acceptance of employer-based qualification schemes,in case the written practice does comply with ISO 9712qualification scheme.
Sec.7 [3.2] Clarification of requirements for NDT operators.
Sec.7 [3.3] Added requirements to NDT supervisors.
IACS UR W35 - Requirementsfor NDT Suppliers
Sec.7 [4] Added requirements to the use and documentation of NDTequipment for operators.
Definition of NDT supplier andwet-welding
Sec.1 Table 3 Added the terms NDT supplier and wet welding.
WPQR recognition Sec.1 Table 6 WPQR's may be recognized by DNV GL if the WPQTs have beenwitnessed and approved by a party recognized by the Society.
Part 2 Chapter 4 Changes - current
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 4Fabrication and testing
DNV GL AS
Topic Reference Description
Added Guidance Note Sec.2 [1.1.2] Defines the user for which the specific NDT requirements arenot applicable.
Welder certification Sec.3 [2.1.1] Specification of who may certify welders. It was not clearwhether welders qualification records according to AWS orASME standard are valid without a DNV GL or third partyendorsement. To make this more clear the rules have beenaligned accordingly.
WPQT hardness indentation inbutt weld
Sec.5 [3.2.7] Two additional indentations in the HAZ shall be made at adistance < 0.5 mm between the centrepoint of the indentationand the fusion line.
WPQT impact test requirementfor thin material below 6 mm
Sec.5 [3.2.9] For cryogenic service where thin material is used the impacttesting shall be included for the welding procedure qualification.
WPQT for pipe, tube or hollowsection
Sec.5 [3.3.1] Added guidance note to explain the term 'pipe'.
WPQT bend test requirementfor pipes
Sec.5 [3.3.2] Same wording for the bend test requirement for pipes andplates.
WPQT NDT requirements Sec.5 [4.1.1], Sec.5[4.2.1]
Aligned the NDT acceptance criteria for butt welds: undercut,excess weld metal, incorrect weld toe and excess penetrationfor which level C applies, and for fillet welds: undercut,incorrect weld toe, excessive convexity and excessive throatthickness for which level C applies.
WPQT, change of consumablebrand for COD steels shall leadto a new qualification test
Sec.5 [6.2.6] If the consumable brand will be changed the CTOD properties ofthe new consumable brand shall be qualified prior to the use inproduction.
WPQT/WPT Charpy V-notchtesting for austenitic steels areonly to be taken from the weldmetal
Sec.5 [9.2.3] Removed the HAZ Charpy V-notch testing for austenitic steels.Alignment with former DNV GL rules.
Cold forming of welded plates Sec.6 [5.2.8] If cold forming is applied on welded plates, pre-qualificationtests may be required depending on the deformation rate, thematerial and welding consumable properties.
MT after removal of temporaryJIG on VL D/E47
Sec.6 [5.3.20] According to Sec.7 Table 3, 100% MT is required for very thickstructural steel in the upper hull of container ships. Therefore100% MT shall be also applied after the removal of temporaryJIG.
Editorial correctionsIn addition to the above stated changes, editorial corrections may have been made.
Part 2 Chapter 4 Changes - current
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 5Fabrication and testing
3 Workmanship and supervision...........................................................263.1 General..........................................................................................26
Section 3 Qualification of welders........................................................................ 281 General.............................................................................................. 281.1 Scope............................................................................................ 281.2 Required compliance documentation..................................................281.3 Documentation requirements............................................................281.4 Survey, inspection and testing requirements...................................... 281.5 Requirements for welding operators.................................................28
2 Qualification testing and certification process of welders.................292.1 General........................................................................................292.2 Certification process...................................................................... 29
Part 2 Chapter 4 Contents
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 6Fabrication and testing
DNV GL AS
Section 4 Welding consumables............................................................................301 General.............................................................................................. 301.1 Scope............................................................................................ 301.2 Required compliance documentation..................................................301.3 Documentation requirements............................................................301.4 Survey, inspection and testing requirements...................................... 301.5 Basic groups and grades..................................................................30
2 Welding procedure specification........................................................402.1 General..........................................................................................402.2 Approval of welding procedure specification........................................41
3 Welding procedure qualification test assembly and sampling oftest pieces............................................................................................ 423.1 General..........................................................................................423.2 Butt welds in plates........................................................................ 423.3 Butt welds in pipes......................................................................... 493.4 Full penetration TKY joints for plates.................................................503.5 Branch connection...........................................................................523.6 Fillet welds.....................................................................................53
4 Non-destructive testing of test assemblies........................................584.1 Full penetration butt joints and T-, K-, and Y-joints.............................584.2 Fillet welds and partial penetration welds...........................................58
5 Acceptance criteria of mechanical testing......................................... 595.1 Transverse tensile test.....................................................................595.2 Bend test.......................................................................................595.3 Macrosection and hardness testing....................................................595.4 Impact testing................................................................................595.5 Cruciform joint tensile-shear strength................................................615.6 Welds between different material grades........................................... 615.7 Fracture mechanics test...................................................................625.8 Retesting....................................................................................... 62
Part 2 Chapter 4 Contents
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 7Fabrication and testing
DNV GL AS
6 Validity of approved welding procedures...........................................626.1 General..........................................................................................626.2 Range of qualification......................................................................63
7 Additional requirements for welding procedure qualification test ofVL D/E47.............................................................................................. 697.1 Test requirements........................................................................... 69
8 Additional requirements for welding procedure qualification test ofall COD grades......................................................................................708.1 General..........................................................................................708.2 Welds in plates...............................................................................708.3 Further limitations to the range of qualification...................................71
9 Additional requirements for welding procedure qualification testfor liquefied gas systems..................................................................... 719.1 General..........................................................................................719.2 Welds in plates and pipes................................................................ 719.3 Test requirements........................................................................... 719.4 Weld production test (WPT) requirements.......................................... 72
10 Additional requirements for welding procedure qualification testof ferritic-austenitic stainless steel (duplex)........................................7210.1 Test requirements......................................................................... 7210.2 Validity of a qualified welding procedure.......................................... 73
11 Additional requirements for welding procedure qualification testof austenitic steel.................................................................................7311.1 Welds in plates and pipes.............................................................. 7311.2 Test requirements......................................................................... 7311.3 Range of approval.........................................................................74
12 Welding procedures qualification for aluminium..............................7412.1 General........................................................................................7412.2 Butt welds in plates...................................................................... 7412.3 Butt welds in pipes....................................................................... 7512.4 Branch connections....................................................................... 7612.5 Fillet welds...................................................................................7612.6 Mechanical testing.........................................................................7712.7 Range of qualification.................................................................... 7812.8 Retesting......................................................................................80
13 Welding procedure qualification, copper alloys................................8113.1 Pipes, plates, castings and other product forms, not includingpropeller castings................................................................................. 8113.2 Copper alloy castings for propellers.................................................81
14 Welding procedure qualification, repair welding of steel castings....83
Part 2 Chapter 4 Contents
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 8Fabrication and testing
DNV GL AS
14.1 General........................................................................................8314.2 Welding procedure qualification test................................................ 8414.3 Range of validity...........................................................................84
7 Inspection, survey and tolerances.....................................................927.1 General..........................................................................................927.2 Alignment and straightness..............................................................937.3 Weld production test requirements....................................................93
Section 7 Non destructive testing of welds...........................................................941 General.............................................................................................. 941.1 Scope............................................................................................ 941.2 Required compliance documentation..................................................941.3 Documentation requirements............................................................941.4 Survey, inspection and testing requirements...................................... 941.5 Basic requirements......................................................................... 95
2 Non-destructive testing procedures and reports................................962.1 General..........................................................................................962.2 Visual testing................................................................................. 96
Part 2 Chapter 4 Contents
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 9Fabrication and testing
2 Procedures for testing tanks and tight boundaries - SOLAS ships.... 1042.1 General........................................................................................1042.2 Application................................................................................... 1042.3 Test types and definitions.............................................................. 1042.4 Test procedures............................................................................ 1052.5 Test requirements for tanks and boundaries..................................... 108
3 Procedures for testing tanks and tight boundaries - Non-SOLASships and SOLAS exemption/equivalent ships.................................... 1123.1 General........................................................................................1123.2 Application................................................................................... 112
Section 9 Hull survey for new construction of bulk carriers and oil tankers........ 1141 General............................................................................................ 1141.1 Application................................................................................... 114
2 Examination and test plan for newbuilding activities.......................1142.1 Requirements................................................................................114
4 Ship construction file.......................................................................115
Part 2 Chapter 4 Contents
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 10Fabrication and testing
DNV GL AS
4.1 General........................................................................................1154.2 Content of ship construction file......................................................1154.3 Review of ship construction file.......................................................122
5 Determination of number of surveyor(s)......................................... 1225.1 General........................................................................................122
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 11Fabrication and testing
DNV GL AS
SECTION 1 GENERAL
1 Introduction
1.1 Objective
1.1.1 This chapter provides requirements for fabrication and testing of welded structures and components.
1.2 Scope
1.2.1 This chapter contains requirements for:
— builders, manufacturers and subcontractors— qualification of welders— welding consumables— welding procedures— fabrication and tolerances— non-destructive testing of welds— structural and tightness testing— goal-based ship construction standards for bulk carriers and oil tankers.
1.3 Application
1.3.1 Fabrication shall be carried out by certified/qualified welders and qualified welding operators withapproved welding procedures and approved welding consumables.
1.3.2 Welding of important components shall be carried out by an approved welding workshop (WWA). Thisis applicable to welding of components like, but not limited to:
— hull equipment, see Table 1— machinery and systems, see Table 1.
1.3.3 Companies performing permanent underwater wet-welding, shall have a welding workshop approval(WWA).
1.3.4 Welding workshop approval (WWA), as given in [1.3.2], is not required for:
— builders and their subcontractors for hull structure— repairs or alterations to fleet in service (except permanent underwater wet-welding repairs)— welding carried out by an approved manufacturer (AoM) qualified for welding.Upon agreement with the Society, WWA may be waived for manufacturers and workshops subject to othermeans of fabrication review by the Society where the scope of WWA is already sufficiently covered.
Table 1 Applicable items
Item References
Hull equipment and appendages
— Anchors Pt.3 Ch.11 Sec.1
— Windlass and chain stoppers Pt.3 Ch.11 Sec.1
Part 2 Chapter 4 Section 1
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 12Fabrication and testing
— Windows, side scuttles and skylights Pt.3 Ch.12 Sec.6
Lifting appliance
— Crane (safety related structure components like crane jibs, crane houses, crane columns,foundations, hydraulic cylinders for lifting gear and luffing gear as well as for telescopiccrane booms, derrick heel bearing and rotary bearing, screws for slew rings, load-bearingcomponents of loose gear, axles, winch drums, winch frames, etc.)
DNVGL-ST-0377
— Crane (safe operation related components like hydraulic cylinders for slewing mechanisms,fittings, lateral wind bracings, rope-sheaves, hoisting eyes)
DNVGL-ST-0377
— Special lifting appliances DNVGL-ST-0377
— Accessories, such as: hooks, blocks, shackles, swivels, rings, chains, claws, clamps, pliers,load fastening ropes (slings/strops), lifting straps, etc.
DNVGL-ST-0377
— Launching appliances LSA Code
— Accommodation ladder and gangway MSC.1/Circ.1331
Rotating machinery
— Combustion engine, bed plate, thrust bearing Pt.4 Ch.3 Sec.1
— Rotating parts and casing of turbochargers and turbines Pt.4 Ch.3 Sec.1
— Shafts for propulsion including shaft for electric propulsion motor Pt.4 Ch.4 Sec.1
— Gears and other power transmitting parts Pt.4 Ch.4 Sec.2
— Waterjet Pt.4 Ch.5 Sec.2
Part 2 Chapter 4 Section 1
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 13Fabrication and testing
DNV GL AS
Item References
— Podded and geared thrusters Pt.4 Ch.5 Sec.3
Piping system
— Class I and class II piping systems Pt.4 Ch.6 Sec.10
— Piping for chemical cargo system Pt.5 Ch.6 Sec.1
— Piping for gas cargo system Pt.5 Ch.7 Sec.1
Steering gear
— Tiller Pt.4 Ch.10 Sec.1
— Welded parts of rudder actuator, power piping valves, flanges and fittings and all steeringgear components transmitting mechanical forces to the rudder stock
Pt.4 Ch.10 Sec.1
1.4 Relation to other Society documents
1.4.1 Where specific or additional requirements are provided in other parts of the rules, the specific oradditional requirements are prevailing.
2 References
2.1 External references
2.1.1 The external references given in Table 2 are referred in this chapter.Unless otherwise agreed or stated in Table 2, the latest version of the referred standards valid at the date ofrelease for the current rules is applicable.
Table 2 References
Reference Title
ANSI/ASNT CP-189 ASNT Standard for Qualification and Certification of Nondestructive Testing Personnel
ANSI/AWS D1.1 Structural welding code - steel
ASME BPVC IX Boiler and Pressure Vessel Code, Section IX: Welding and Brazing Qualifications
ASME BPVC V Boiler and Presure Vesel Code, Section V: Nondestructive Examination
ASTM E165 Standard Practice for Liquid Penetrant Testing for General Industry
ASTM E562 Standard test method for determining volume fraction by systematic manual point count
ASTM G48 Standard test methods for pitting and crevice corrosion resistance of stainless steels andrelated alloys by use of ferric chloride solution
EN 1011-1 Welding – Recommendations for welding of metallic materials – General guidance for arcwelding
EN ISO 5817 Welding – Fusion-welded joints in steel, nickel, titanium and their alloys (beam weldingexcluded) – Quality levels for imperfections
Part 2 Chapter 4 Section 1
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 14Fabrication and testing
DNV GL AS
Reference Title
EN ISO 6520-1 Welding and allied processes – Classification of geometric imperfections in metallic materials –Part 1: Fusion welding
EN ISO 9712:2012 Non-destructive testing – Qualification and certification of NDT personnel (or later revision)
EN ISO 10042 Welding – Arc-welded joints in aluminium and its alloys – Quality levels for imperfections
EN ISO 17635 Non-destructive testing of welds – General rules for metallic materials
IACS Rec. No.47 Shipbuilding and repair quality standard
IACS UR S14 Testing procedures of watertight compartments
IACS UR W11 Normal and higher strength hull structural steels
IACS UR W17 Approval of consumables for welding normal and higher strength hull structural steels
IACS UR Z23 Hull survey for new construction
ISO 148 Metallic materials – Charpy pendulum impact test
ISO 3452:2013 Non-destructive testing – Penetrant testing (or later revision)
ISO 3834-2 Quality requirements for fusion welding of metallic materials – Part 2: Comprehensive qualityrequirements
ISO 4063 Welding and allied processes – Nomenclature of processes and reference numbers
ISO 6507-1 Metallic materials – Vickers hardness test – Part 1: Test method
ISO 9001 Quality management systems – Requirements
ISO 9015-1 Destructive tests on welds in metallic materials – Part 1: Hardness test on arc welded joints
ISO 9606 Qualification testing of welders - Fusion welding
ISO 11666:2018 Non-destructive testing of welds – Ultrasonic testing – Acceptance levels (or later revision)
ISO 10675:2016 Non-destructive testing of welds – Acceptance levels for radiographic testing (or later revision)
ISO 14175 Welding consumables – Gases and gas mixtures for fusion welding and allied processes
ISO 14341 Welding consumables – Wire electrodes and weld deposits for gas shielded metal arc welding ofnon-alloy and fine grain steels – Classification
ISO 14731 Welding coordination – Tasks and responsibilities
ISO 14732 Welding personnel – Qualification testing of welding operators and weld setters for mechanizedand automatic welding of metallic materials
ISO 15614-6Specification and qualification of welding procedures for metallic materials –
Welding procedure test – Part 6: Arc and gas welding of copper and its alloys
ISO 15614-7 Specification and qualification of welding procedures for metallic materials – Welding proceduretest - Part 7: Overlay welding
ISO 15626:2018 Non-destructive testing of welds - Time-of-flight diffraction technique (TOFD) - Acceptancelevels (or later revision)
ISO 19285:2017 Non-destructive testing of welds - Phased array ultrasonic testing (PAUT) - Acceptance levels(or later revision)
Part 2 Chapter 4 Section 1
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 15Fabrication and testing
DNV GL AS
Reference Title
ISO 17662 Welding – Calibration, verification and validation of equipment used for welding, includingancillary activities
ISO 23277:2015 Non-destructive testing of welds – Penetrant testing of welds - Acceptance levels (or laterrevision)
ISO 23278 Non-destructive testing of welds – Magnetic particle testing of welds – Acceptance levels
ISO 25239 Friction stir welding - Aluminium
ISO/IEC 17020 Conformity assessment - Requirements for the operation of various types of bodies performinginspection
ISO/IEC 17025 General requirements for the competence of testing and calibration laboratories
LSA-Code International Life-Saving Appliances Code (LSA), IMO Resolution MSC.320(89)
MSC.1/Circ.1331 Guidelines for the construction, installation, maintenance and inspection/survey of means ofembarkation and disembarkation
SOLAS I-A/3 Ch. I: General Provisions – Part A: Applications, definitions, etc. – Regulation 3: Exceptions
SOLAS II-1 Ch. II-1: Construction - Structure, subdivision and stability, machinery and electricalinstallations
2.2 Terminology and definitions
2.2.1 General terminology and definitions are given in Pt.1 Ch.1 Sec.1 [1.2]. Further definitions are given inTable 3.
Table 3 Definitions
Term Definition
Automatic weldingCovers fully automatic processes, where all operations are mechanized and fullymechanized welding, where all main operations (excluding the handling of the workpiece) are mechanized.
Essential variables/parameters
Welding parameters essential for the range of validity of a welding procedure, see Sec.5[6.2].
Heat input
Energy introduced into the weld region during welding. Heat input is calculated asfollows:
In case the heat input is corrected for thermal efficiency in accordance with EN 1011-1,the thermal efficiency coefficient shall be stated.
For multi-wire welding, the heat input is calculated as the sum of the heat inputscalculated separately for each wire. This do not apply if the interpass temperaturebetween each wire is 250°C or lower.
For the waveform controlled welding power supply, the heat input calculation equationsgiven in ASME Sec.IX QW-409.1 may be used.
Inspection An activity carried out by the builder or subcontractor to verify compliance with theapplicable rules and specifications.
Part 2 Chapter 4 Section 1
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 16Fabrication and testing
DNV GL AS
Term Definition
Inspection body
An impartial body having the organisation, staffing, competence and integrity to performto specified criteria functions such as assessing, recommending for acceptance andsubsequent audit of manufacturers´ quality control operations, and selection andevaluation of products on site or in factories or elsewhere as directed, to specifiedcriteria.
Manual welding Welding where the electrode holder, welding hand gun, torch or blowpipe is manipulatedby hand.
NDT supplier Entity, individual, partnership, company, company sub division, corporation, association,or other service provider providing NDT services.
Newbuilding surveyarrangement (NSA)
Agreement between the builder and the Society defining responsibility and authority ofpersonnel and items to be controlled with acceptance criteria, quality control functions.The activities through this agreement are complementary to the Society’s own surveyscheme.
Probability of detection (POD) Indicates the probability that a testing technique will detect a given flaw.
Semi-automatic welding Same as partly mechanized welding: manual welding where the wire feed is mechanized.
Quality management systemQuality management system worked out in accordance with a reputable quality standard,such as ISO 9001 or equivalent. The quality management system may be required to becertified by an accredited certification body.
SupervisorResponsible person who provides specific knowledge / expertise and who coordinates,monitors and regulates employees and their performance of assigned or delegated tasks,e.g. for welding and NDT.
Subcontractor Independent unit performing work under supervision by the builder.
Welding, brazing, spraying
The term 'welding', used in these rules also cover all other special thermal and/ormechanized joining processes such as brazing, spraying, etc. which require also pre-qualification for the personnel like brazer/sprayer tests or the procedures like brazing/spraying procedures. These rules shall be applied in an analogous manner to thesespecial processes. Where no special provisions are made in these rules, the nature andscope of the pre-qualification tests and quality assurance measures required will bespecified by the Society on a case-by-case basis.
WeldingJoining process in which two or more parts are united producing a continuity in thenature of the workpiece material(s) by means of heat or pressure or both, and with orwithout the use of filler material.
Wet-welding Welding at ambient pressure with the welder/diver in the water and with no mechanicalbarrier around the arc.
2.3 Abbreviations and symbols
2.3.1 Abbreviations and symbols are given in Ch.1 Sec.1.
Part 2 Chapter 4 Section 1
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 17Fabrication and testing
DNV GL AS
3 Procedural requirements
3.1 Required compliance documentation3.1.1 Organisations and personnelGeneral certification requirements are given in Ch.1 Sec.1 [3.1]. In addition, organisations and personnelshall be certified as required by Table 4.
Part 2 Chapter 4 Section 1
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 18Fabrication and testing
DNV GL AS
Table 4 Compliance documents for organisations and personnel
Object Certificatetype Issued by Certification
standard* Additional description
Welding workshops WWA Society *)
The welding workshop shall be approvedfor important components e.g. for weldingof hull equipment, machinery and systems,permanent underwater wet-welding(including permanent repairs or alterationsto fleet in service with underwater wet-welding).
WWA certificate is not required for:
— builders and their subcontractors forhull structure
— repairs or alterations to fleet in service— welding carried out by an approved
manufacturer (AoM) qualified forwelding.
WeldersWelders
certificate/qualification
Society See Sec.3 To be certified/qualified, see Sec.3.
Tack weldersWelders
certificate/qualification
Society See Sec.3If the tack weld is not removed priorto production welding, see certificationrequirements for welders.
Welding operators - - See Sec.3 Welding operators shall be qualified but,not necessarily certified.
NDT supervisors /operators - - See Sec.7
Level 3 (supervisors)/Level 2 (operators)shall be certified according to a schemerecognized by the Society, see Sec.7 [3],level 3 personnel shall be certified by anaccredited certification body.
*) Unless otherwise specified the certification standard is DNV GL rules.
Part 2 Chapter 4 Section 1
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 19Fabrication and testing
DNV GL AS
3.1.2 MaterialsWelding related materials shall be certified as required by Table 5.
Table 5 Certification requirements for welding related materials
ObjectCompliancedocumenttype
Issued by Compliancestandard* Additional description
Welding consumables TA Society See Sec.4
Welding consumables shall be typeapproved by the Society. See DNVGL-CP-0069.
If the welding consumable is not typeapproved, a welding production test (WPT)or a welding procedure qualification test(WPQT) with one extra all-weld-metaltensile test (round specimen from theweld metal) is required from each batchof consumables, for a project specificapproval of the consumable in question.Further additional tests required for thetype approval of the welding consumable asgiven in DNVGL-CP-0069 may be requirede.g. hydrogen testing or fillet weld tests oradditional welding position like overhead.
Base materials for weldtests MC Society or
manufacturer See Ch.1 and Ch.2 Base materials applied for WPQT.
Shop primers TA Society *) See DNVGL-CP-0109.
*) Unless otherwise specified the compliance standard is DNV GL rules.
3.2 Documentation requirements
3.2.1 Documentation shall be submitted or available as required by Table 6 and Table 7.
Table 6 Documentation requirements – vessel
Object Documentation type Additional description Info 1)
H130 - Fabrication specification For builders unknown to the Society. FI, L, R
Applicable for vessel specific WPQR notalready approved. During qualificationtest welding, all welding parameters, seeSec.5 [2.1.1], shall be recorded for eachwelding pass. The report summarizingthe records from the welding and thetest results, i.e. a welding procedurequalification record (WPQR), shall beprepared. The WPQR shall also give thematerial certificate of the base and fillermaterials applied in the WPQT.
AP, L -when
witnessedby theSociety
FI, L -when
witnessedand
approvedby a partyrecognizedby theSociety
1) FI = For Information, AP = For Approval, L = by Local station, R = on Request. For full definition of abbreviations,see DNVGL-CG-0550 Sec.6.
Table 7 Qualification documentation for builder
Item Documentation type Additional description
Hull survey for newconstruction acc. to IACSUR Z23
Records— The builder shall maintain the records acc. to IACS
UR Z23.— The records shall be presented to the surveyor.
Quality manual Q010 To be submitted for information.
Document controlprocedure Q020 To be submitted for information.
Welding operators Records of proficiency
Evidence that the operators are receiving adequateregularly training in setting, programming andoperating of the equipment (in accordance with anapplicable WPS).
Welders' list Card index or register
Of all for the project relevant certified/qualifiedwelders including information e.g. about welderapproval range, date of initial test, validity, re-test/prolongation, certification body.
Welding consumables Welding consumables list
List of all project relevant welding consumables andauxiliaries, e.g. wire-gas combination and wire-fluxcombinations, the DNV GL type approved grade andthe base materials for which the consumable shall beapplied.
Part 2 Chapter 4 Section 1
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 21Fabrication and testing
DNV GL AS
Item Documentation type Additional description
Procedure for storage and handling
The consumable manufacturer’s recommendationsshall be observed and procedures giving detailsregarding conditions in storage rooms, temperaturein storage ovens and quivers, length of exposure andconditions, as applicable shall be made available.
Welding procedures M060 To be submitted for approval.
Preheating Preheating procedure See Sec.6 [5.3.8].
Forming and straightening Forming and straighteningprocedure
Forming and straightening of materials shall beperformed according to procedures which outline thesuccession of the controlled steps.
Cold forming
Document of manufacturerrecommendation for cold forming
or
Procedure for qualification of coldforming
See Sec.6 [5.2].
NDT procedure M151 To be submitted for approval.
3.2.2 For general requirements for documentation including definitions, see DNVGL-CG-0550.
3.3 Survey, inspection and testing requirements
3.3.1 General survey, inspection and testing requirements are given in Ch.1 Sec.1 [3.3] and in Table 8.Specific requirements are given in the following sections as relevant.
Table 8 Survey and testing requirements
Survey, inspection and testing item Description
Chemical composition The chemical composition shall be analysed as specified in Ch.1Sec.2 [3.3] and meet the requirements given herein.
Welding workshop approval
— the welding workshop shall apply for the welding shopapproval and provide an application together with the weldingworkshop description, as described in the relevant approvalprogramme
— the surveyor shall be given the opportunity to audit theworkshop and survey all relevant processes and tests prior tostart of fabrication.
Mechanical properties including impact toughness,fracture mechanics, crack arrest properties, etc.
Mechanical properties shall be determined as specified in Ch.1and meet the requirements given herein.
Part 2 Chapter 4 Section 1
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 22Fabrication and testing
DNV GL AS
Survey, inspection and testing item Description
Non-destructive testing
— non-destructive tests shall be performed under the builder’s/manufacturer’s responsibility
— non-destructive testing shall be performed as specified inSec.7 and meet the requirements given therein
— the NDT supplier providing a professional service hasimplemented written procedures for training, experience,education, examination, certification, performance,application, control, verification and reporting of NDT. Thesurveyor shall be furnished with proof thereof if he/she sorequests
— the testing operators shall be certified in accordance with ISO9712:2012 (or later version), ASNT ACCP or equal, as wellas adequately qualified for this task. The surveyor shall befurnished with proof thereof if he/she so requests
— when required, the surveyor shall be given the possibility tobe present during non-destructive tests, See DNVGL-CG-0051
— the Society shall be provided with access to all relevant partsof the works, and are to be provided with necessary facilitiesand information to verify that NDT has been carried out inaccordance with approved procedures.
Testing of welding consumables
— the appropriate type approval tests shall be carried outbefore the welding consumables are dispatched from themanufacturer
— if the necessary facilities are not available at themanufacturer's works, the testing shall be carried out at arecognized testing laboratory
— where the Society's certification is required, all the testing(except for chemical composition analysis) shall be witnessedby the surveyor, unless otherwise agreed
— the surveyor may require further tests when deemednecessary
— all tests shall be carried out by competent personnel onmachines of accepted type. See DNVGL-CP-0069.
Testing of shop primerWhere the Society's certification is required, all testing shall bewitnessed by the surveyor, unless otherwise agreed. See DNVGL-CP-0109.
Welder tests
Welding and testing of weld assemblies for welder certification bythe Society shall be performed in the presence of the Society’srepresentative. Upon successful completion, and on client’srequest, the Society will certify that the welder has passed theapproval testing.
Welding procedure tests
The welding procedure tests shall be arranged according tothe requirements stated in Sec.5. Welding and testing of weldassemblies for welding procedure qualification shall be performedin the presence of the Society’s representative.
Part 2 Chapter 4 Section 1
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 23Fabrication and testing
DNV GL AS
SECTION 2 REQUIREMENTS FOR BUILDERS
1 General
1.1 Scope
1.1.1 This section specifies general requirements for builders, involved in building activities of structuresand components intended for classification by the Society. This section shall also apply to subcontractors ofbuilders, when performing fabrication under the Society’s scope of classification.
1.1.2 All builders and subcontractors shall comply with the criteria given in Pt.1 Ch.1 Sec.2 [1.2.1] and IACSUR Z23 Hull Survey for New Construction and provide the documentation stated. For bulk carriers and oiltankers further requirements according to Sec.9 are given.
Guidance note:The specific requirements for NDT suppliers are not applicable for manufacturers holding approval of manufacturer certificate(AoM) or welding workshop certificate (WWA) for the building activities covered by the AoM or WWA certificate. For NDT suppliersholding approval of service supplier (AoSS) certificate by the Society according to DNVGL-CP-0484 App.B[4], compliance with thespecific requirements for NDT suppliers is already considered confirmed.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
1.2 Documentation requirements
1.2.1 General documentation requirements are given in Sec.1 [3.2]. Specific documentation requirementsfor NDT suppliers are given in [1.2.2].
1.2.2 The NDT supplier shall document, as required below, that it has the competence and control needed toperform the specified services.The following documents shall be available:
— an outline of supplier's organisation and management structure, including any subsidiaries— information on the structure of the supplier’s quality management system— quality manual and documented procedures covering the requirements given in Sec.7 [2.2.1]— for companies with in-house certification of persons scheme, a written practice developed in accordancewith a recognised standard or recommended practice (i.e. ASNT’s SNT-TC-1A, 2016, ANSI/ASNT CP-189,2016 or similar)
— operational work procedures for each NDT method including selection of the NDT technique— training- and follow-up programmes for NDT operators including practical training on various ship andoffshore products
— procedure for supervisor’s authorisation of NDT operators— experience of the supplier in the specific service area— a list of documented training and experience for NDT operators within the relevant service area, includingqualifications and third party certification per ISO 9712:2012 (or later version) based certificationschemes
— description of equipment(s) used for the services performed by the supplier— a guide for NDT operators to use equipment mentioned above— record formats for recording results of the services referred to in item— information on other activities which may present a conflict of interest— record of customer claims and corrective actions— any legal proceedings against the company in the past/currently in the courts of law.
Part 2 Chapter 4 Section 2
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 24Fabrication and testing
DNV GL AS
The NDT supplier shall give information of agreements and arrangements if any part(s) of the servicesprovided are subcontracted. The NDT supplier, in the follow-up of subcontracs, shall give emphasis to thequality management system of the subcontractor.Subcontractors shall meet the same requirements placed on the NDT suppliers for the NDT performed.See also requirements to the NDT supplier’s quality management system in [2.1.2].
1.3 Survey, inspection and testing requirements
1.3.1 Survey, inspection and testing requirements are given in Sec.1 [3.3]. Additional specific requirementsare given in Table 1, as further detailed in this section.
Table 1 Additional survey and testing requirements
Survey, inspection and testing item Description
Hull survey for new construction in accordance withIACS UR Z23
Survey and testing requirements are covered by the Society'srules, IACS UR Z23 and Sec.9.
Part 2 Chapter 4 Section 2
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 25Fabrication and testing
DNV GL AS
2 Survey arrangement
2.1 Quality management system
2.1.1 Builders of hull structures shall possess a documented and implemented quality management system.If not, the Society will consider an extended survey scheme. The extent of the quality management systemshall be dependent on the size and type of the organization, complexity and interaction of the processes andpersonnel competence.
2.1.2 The NDT supplier shall have a documented quality system complying with the ISO/IEC 17020:2012(or later version), and should satisfy the requirements of Type A or Type B inspection body. The documentedquality management system shall cover at least:
— work procedures for all tasks and operations, including the various NDT methods and NDT techniques forwhich the supplier is involved
— preparation, issuance, maintenance and control of documents— maintenance and calibration of the equipment— training programmes for the NDT operators and the supervisors— maintenance of records for NDT operators’ and the supervisors’ training, qualification and certification— certification of NDT operators including re-validation and re-certification— procedure for test of operators’ visual acuity— supervision and verification of operation to ensure compliance with the NDT procedures— quality management of subsidiaries— job preparation— order reference system where each engagement is traceable to when, who and where the test was carriedout
— recording and reporting of information, including retention time of records— code of conduct for the supplier's activities, especially the NDT activities— periodic review of work process procedures— corrective and preventive action— feedback and continuous improvement— internal audits— the provision of accessibility to required codes, standards and procedures to assist NDT operators.
3 Workmanship and supervision
3.1 General
3.1.1 Builders and subcontractors shall ensure that the work is executed in accordance with fabricationprocedures and work instructions, inspection and test plans.
3.1.2 Builders shall ensure that the work is effectively and systematically controlled at all stages.Builders and subcontractors shall prove and document their abilities to carry out the welding operations inquestion. Further:
— builders and subcontractors shall inspect welding operations by the use of necessary equipment in orderto assure compliance with the welding procedures
— builders shall present the results of own and subcontractors inspections before surveys by the Society— important welding operations shall be carried out under daily supervision of a nominated qualified andexperienced welding supervisor/inspector. The work of each welder shall be regularly examined.
Part 2 Chapter 4 Section 2
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 26Fabrication and testing
DNV GL AS
3.1.3 Builders shall be in control of work performed at the location of subcontractors and of subcontractorsperforming work at the builders.
Part 2 Chapter 4 Section 2
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 27Fabrication and testing
DNV GL AS
SECTION 3 QUALIFICATION OF WELDERS
1 General
1.1 Scope
1.1.1 These requirements apply to the Society’s acceptance of welders and welding operators for fusionwelding of steel and non-ferrous metals.
1.2 Required compliance documentation
1.2.1 Compliance documentation requirements are given in Sec.1 [3.1]. Additional requirements are given in[2.1.1], [2.1.4] and [2.2].
1.3 Documentation requirements
1.3.1 Documentation requirements are given in Sec.1 [3.2].
1.4 Survey, inspection and testing requirements
1.4.1 General survey, inspection and testing requirements are given in Sec.1 [3.3]. Additional specificrequirements are given in Table 1, as further detailed in this section.
Table 1 Additional survey and testing requirements
Survey, inspection and testing item Description
Welders' list The surveyor shall be allowed to examine the register at any time.
1.5 Requirements for welding operators
1.5.1 The welding operator responsible for setting up and/or adjustment of fully mechanized and automaticequipment, such as submerged arc welding, gravity welding, electro-gas welding and metal active gaswelding with auto-carriage, etc., shall be qualified whether he operates the equipment or not. For this,records of proficiency, which give evidence that he is receiving adequate regularly training in setting,programming and operation functions of the equipment (in accordance with applicable WPS's) are required.
1.5.2 For a welding operator who solely operates the equipment without responsibility for setting up oradjusting it, the builder shall ensure that he has adequate experience and that he produces welds of requiredquality. For this, records of proficiency, which gives evidence that he is receiving regularly adequate trainingin operation functions of the equipment (in accordance with applicable WPS's) are required.
1.5.3 In addition to the requirements of [1.5.1] and [1.5.2], the training of welding operators shall includetraining in evaluation of:
— grove dimensions according to WPS— grove cleanliness requirements— weather and wind requirements— handling of welding consumables.
Part 2 Chapter 4 Section 3
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 28Fabrication and testing
DNV GL AS
Appropriate records of training shall be maintained.Guidance note:Alternatively to training records, welding operators certificates according to a recognized standard may be accepted, e.g. ISO14732, ASME BPVC IX or ANSI/AWS D1.1.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
2 Qualification testing and certification process of welders
2.1 General
2.1.1 Welders shall be certified/qualified by the Society or by a recognised third party (see[2.2.2]), to astandard recognised by the Society, e.g. ISO 9606, ASME BPVC IX, ANSI/AWS D1.1.
Guidance note:IACS UR W32 is a recognised qualification scheme for welders of hull structural steels.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
2.1.2 Recognition of other standards is subject to acceptance by the Society.
2.1.3 The training of welders, control of their qualification and maintenance of their skills are theresponsibility of the builders and subcontractors. When requested, this shall be documented anddemonstrated to the satisfaction of the Society.
2.1.4 Builders and subcontractors shall keep a register of all certified/qualified welders. The register shallgive information on welders training, and date and results of qualification tests. Information about the basemetal, type of welding consumable, welding process, type of welded joint, material thickness and weldingposition shall be stated in the event of re-qualification tests.
2.1.5 A welder's certificate/qualification shall be validated every 6 months and in accordance with thecertification standard. Records thereof are required.
2.1.6 The surveyor shall be allowed to examine the register at any time and the records/evidence shall beprovided according to the relevant standards.
2.2 Certification process
2.2.1 Welding and testing of weld assemblies for welder certification by the Society shall be performed in thepresence of the Society's representative. Upon successful completion, and on client's request, the Society willcertify that the welder has passed the approval test.
2.2.2 Where certification is performed by another recognized classification Society or independentorganisations, recognition of such certification will be evaluated on a case by case basis. The Society reservesthe right to require verification of welders qualifications when deemed necessary. Such verification mayinclude testing prior to production, extra NDT and/or welding production tests (WPT).
Guidance note:An independent organisation may be an accredited or nationally approved certification body.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
Part 2 Chapter 4 Section 3
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 29Fabrication and testing
DNV GL AS
SECTION 4 WELDING CONSUMABLES
1 General
1.1 Scope
1.1.1 This section specifies basic groups and grades for type approved welding consumables, application ofthe various grades, and grouping of the shielding gases.
1.2 Required compliance documentation
1.2.1 Required compliance documentation are given in Sec.1 [3.1].
1.3 Documentation requirements
1.3.1 Documentation requirements are given in Sec.1 [3.2].
1.4 Survey, inspection and testing requirements
1.4.1 General survey, inspection and testing requirements are given in Sec.1 [3.3].
1.5 Basic groups and grades
1.5.1 Welding consumables are divided into groups, depending on the strength of the filler metal,corresponding to the strength of the steel grade to be welded. The applicable groups are:
— normal strength steels— high strength steels— extra high strength steels— boiler and pressure vessel steels— steels for low temperature service— stainless steels— aluminium alloys.
The groups are further divided into grades depending on the impact test temperature and the chemicalcomposition of the filler metal. The grades of welding consumables are specified in Table 1.
Part 2 Chapter 4 Section 4
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 30Fabrication and testing
DNV GL AS
Table 1 Correlation of welding consumables to hull structural steels
Normalstrength steels High strength steels Extra high strength steels Austenitic
stainless steels
Grade of weldingconsumables
1
2
3
I
II
III
2 Y
3 Y
4 Y
5 Y
2/3/4/5 Y40
I Y
II Y
III Y
IV Y
V Y
II/III/IV/V Y40
3/4/5 Y42
III/IV/V Y42
3/4/5 Y46
III/IV/V Y46
3/4/5 Y50
III/IV/V Y50
3/4/5 Y55
III/IV/V Y55
3/4/5 Y62
III/IV/V Y62
3/4/5 Y69
III/IV/V/ Y69
3/4 Y89
III/IV Y89
3/4 Y96
III/IV Y96
308/308Mo/308L
309/309L/309Nb/
309Mo/309MoL
310/310Nb/310Mo
312
316/316L
317/317L
318
330
347
349
1) grades 1, 2, 3, 4 and 5 are referring to covered electrodes; grades I, II, III, IV and V are referring to otherconsumables
2) increasing number means increasing impact toughness test requirements (test temperature grade 1/I: 20ºC, grade5/V: -60ºC)
3) Y means high strength steels4) Y followed by a number means extra high strength steels of corresponding strength (×10).
1.5.2 Type approved welding consumables for austenitic stainless steels and ferritic-austenitic (duplex) steelsshall be selected in accordance with manufacturers recommendations for the applicable grade of steel, takingthe corrosion resistance, strength requirements and the welding metallurgy (including resistance to hotcracking) into account.
1.5.3 Welding consumables which have satisfied the requirements for a higher toughness grade areconsidered to comply with the requirements for a lower toughness grade of the same group.
1.5.4 Recommendations for welding consumables for the repair of copper alloys are given in Sec.5 Table 19.
1.5.5 Welding consumables for other non-ferritic materials shall be selected in accordance withmanufacturer's recommendations for the applicable materials, taking the corrosion resistance, strengthrequirements and the welding metallurgy (including resistance to hot cracking) into account.
1.5.6 The following tables (Table 2 to Table 7) show which welding consumables that can be applied forvarious steel grades.For steel grades with minimum specified yield stress 890 and 960 MPa the welding consumables shall, unlessotherwise agreed, give weld deposit with strength and impact toughness properties not below that of thematerial to be welded. The consumables shall have hydrogen mark H5 or better (e.g. H2.5).When two different steel grades shall be joined, the welding consumable shall have yield strength not belowthat of the lower strength steel.
Part 2 Chapter 4 Section 4
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 31Fabrication and testing
DNV GL AS
Guidance note:When welding high strength steels of grade E, it is recommended that the applied welding consumables have been tested at –40°C(grade 4 or IV).
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
1.5.7 Where applicable, the composition of the shielding gas shall be reported.The approval of a wire/gas combination with any particular gas can be applied to or transferred to, anycombination of the same wire and any gas in the same numbered group as defined in Table 8.
Table 2 Correlation of welding consumables (covered electrodes) to hull structural steels
Grade of welding consumablesHull structuralsteel grade 1 (DP) 2 2 Y 1) 2 Y40 1) 3 3 Y 1) 3 Y40 1) 4 Y 1) 5 Y 1) 4 Y40 1) 5 Y40 1)
VL A X X X X 2) X X X 2) X X X 2) X 2)
VL B X X X 2) X X X 2) X X X 2) X 2)
VL D X X X 2) X X X 2) X X X 2) X 2)
VL E X X X 2) X X X 2) X 2)
VL A27S X X X X X X X X
VL D27S X X X X X X X X
VL E27S X X X X X X
VL A32/36 X X X X X X X X
VL D32/36 X 3) X 3) X X X X X X
VL E32/36 X 3) X 3) X X X X
VL F32/36 X 3) X X 3) X
VL A40 X X X X
VL D40 X 3) X X X
VL E40 X 3) X X
VL F40 X 3) X
1) to have hydrogen mark H15, H10 or H52) the welding consumables approved as Y40 may be used for welding of normal strength steel subject to special
agreement with the Society3) for plates with thickness over 50 mm, welding consumables with at least one toughness grade higher shall be used
(e.g. for VL E36: 4Y instead of 3Y).
Table 3 Correlation of welding consumables (other than covered electrodes) to hull structuralsteels
Grade of welding consumablesHull structuralsteel grade 1 I Y II II Y II Y40 III III Y III Y40 IV Y V Y IV Y40 V Y40
VL A X X X X X 1) X X X 1) X X X 1) X 1)
VL B X X X 1) X X X 1) X X X 1) X 1)
Part 2 Chapter 4 Section 4
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 32Fabrication and testing
DNV GL AS
VL D X X X 1) X X X 1) X X X 1) X 1)
VL E X X X 1) X X X 1) X 1)
VL A27S X X X X X X X X X
VL D27S X X X X X X X X
VL E27S X X X X X X
VL A32/36 X2) X X X X X X X X
VL D32/36 X 2) X 2) X X X X X X
VL E32/36 X 2) X 2) X X X X
VL F32/36 X 2) X X 2) X
VL A40 X X X X
VL D40 X 2) X X X
VL E40 X 2) X X
VL F40 X 2) X
1) the welding consumables approved as Y40 may be used for welding of normal strength steel subject to specialagreement with the Society
2) for plates with thickness over 50 mm, welding consumables with at least one toughness grade higher shall be used(e.g. for VL E36: IV Y instead of III Y).
Table 4 Correlation of welding consumables (covered electrodes) to boilers and pressure vesselsteels and steels for low temperature service
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 34Fabrication and testing
DNV GL AS
VL D460
VL E460
VL F460
3/III, 4/IV, 5/V
4/IV, 5/V
5/V
3/III, 4/IV, 5/V
4/IV, 5/V
5/V
VL D47 2)
t ≤ 50 mm 3/III, 4/IV, 5/V 3/III, 4/IV, 5/V
t > 50 mm 4/IV, 5/V 4/IV, 5/V
VL E47 2)
t ≤ 50 mm 4/IV, 5/V 4/IV, 5/V
t > 50 mm 5/V 5/V
VL D500
VL E500
VL F500
3/III, 4/IV, 5/V
4/IV, 5/V
5/V
3/III, 4/IV, 5/V
4/IV, 5/V
5/V
VL D550
VL E550
VL F550
3/III, 4/IV, 5/V
4/IV, 5/V
5/V
3/III, 4/IV, 5/V
4/IV, 5/V
5/V
VL D620
VL E620
VL F620
3/III, 4/IV, 5/V
4/IV, 5/V
5/V
3/III, 4/IV, 5/V
4/IV, 5/V
5/V
VL D690
VL E690
VL F690
3/III, 4/IV, 5/V
4/IV, 5/V
5/V
1) may have hydrogen mark H52) shall have hydrogen mark H53) the welding consumables approved as Y42 may be used for welding of high strength steel subject to special
agreement with the Society.
Table 7 Selection of suitable consumables for combinations of aluminium alloys
Additional requirements for BCA and COD grade steels, materials for liquefied gas systems and repair weldingof steel castings are also given.
1.1.2 WPS for overlay/clad welding shall be qualified according to ISO 15614-7, ASME IX or anotherrecognized standard.
1.1.3 For welding of clad steel plates (plates consisting of a base material and a thinner layer of claddingmetal on one or both sides), the WPS shall be qualified according to the requirements in this section.For welding of explosion bonded steel-aluminium transition joints for the connection of steel structurewith aluminium structure, the qualifications of WPS for steel part of transition joint to steel structure andfor aluminium part of transition joint to aluminium structure shall follow the requirements of this section.Furthermore, the recommendations for welding given by the manufacturer of the transition joint shall beobserved.
1.1.4 WPS for materials not covered by this section shall be qualified in accordance with a recognizedstandard or a recognized practice accepted by the Society.
1.1.5 Method and general requirements for mechanical testing shall follow Ch.1.
1.1.6 This version of the Society's rules do not invalidate welding procedure qualifications tests made andaccepted by either of the former companies DNV AS or GL SE before 1st of January 2016 provided thewelding procedures are made and accepted according to the DNV or GL classification rules if the validity ismaintained.In case of doubt the Society shall decide whether the already accepted welding procedures can be furtherapplied or not.
1.2 Required compliance documentation
1.2.1 Required compliance documentation is given in Sec.1 [3.1].
1.3 Documentation requirements
1.3.1 Documentation requirements are given in Sec.1 [3.2]. Additional specific documentation requirementsare given in Table 1.
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 37Fabrication and testing
DNV GL AS
Table 1 Qualification documentation for builder
Item Documentation type Additional description
pWPS Preliminary welding procedurespecification
The builder or subcontractor shall submit to the Societya preliminary welding procedure specification (pWPS)for review prior to the WPQT. The pWPS shall give allrelevant parameters as required in [2.1.1].
Instruments for checkingwelding parameters Calibration records
All relevant instruments for checking of weldingparameters e.g. temperature, ampere, volt, appliedfor the WPQT shall have valid calibration certificatesand the adequacy of any control software shall bedocumented to the satisfaction of the surveyor.
1.4 Survey, inspection and testing requirements
1.4.1 General survey, inspection and testing requirements are given in Sec.1 [3.3]. Additional specificrequirements are given in Table 2, as further detailed in this section.
Table 2 Additional survey and testing requirements
Survey, inspectionand testing item Description
Base material used for weldingprocedures The base materials shall be identified by means of material marking and certificates.
Consumables used for weldingprocedures
The consumables shall be approved by the Society. Non-approved consumables maybe accepted for qualification of a WPS.
Non-destructive testingTest pieces for the welding procedure qualification shall be subject to non-destructive testing as specified herein. Waiting time for performance of NDT shall beobserved. NDT shall be carried out before the test piece is dispatched.
WPS WPS shall be approved by the Society prior to production welding.
WPQR
— welding of weld assemblies for welding procedure qualification shall beperformed in the presence of the Society’s representative
— where the Society's certification is required, all the testing (except for chemicalcomposition analysis) shall be witnessed by the surveyor, unless otherwiseagreed.
WPQT for fully mechanized orautomatic welding process
If the test coupon is not welded in the comparable environment as the productioncondition or if the manufacturer has no or limited experience with the processand equipment, the first fabrication welds shall be included as part of the weldingprocedure tests and, as a minimum requirement, shall be subjected to non-destructive testing.
WPT - additional requirements forliquefied gas systems Welding production test is required in accordance with [9.4].
Corrosion test – stainless steels Corrosion tests are required as described in [10] and [11].
Metallographic examination –ferritic-austenitic steels Microstructural examination is required as described in [10].
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 38Fabrication and testing
DNV GL AS
1.5 Wide gap welding
1.5.1 Wide gap welding for butt joints and T-, Y-, and K-joints shall be qualified by a separate WPQT whenthe gap is more than 16 mm and up to maximum 1.5×t (max. 25 mm), where t is the plate thickness of theabutting member. The largest gap in production (for remedial welding) shall be used. Gap more than 1.5xt(or 25 mm) shall, unless specially agreed, be repaired by insert.Buttering of the weld groove shall be qualified by a separate WPQT for the following cases:
— the buttering process essential variables are different from the essential variables of the process used forsubsequent completion of the joint
— the thickness of the buttering exceeds 8 mm.
For the WPQT to be qualified the buttered area shall be 100% tested with MT (ferromagnetic materials) or PT(non-magnetic materials) before the filling of the groove starts. No surface linear indications are accepted.
Guidance note:For typical butt- and fillet weld plate edge preparation repairs, guidance is given to IACS Rec. No.47 Shipbuilding and RepairQuality Standard, Part A.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
1.6 Welding processes
1.6.1 Welding shall be performed with the following processes unless otherwise approved (methodsnumbering system in accordance with ISO 4063):
— 111 Manual metal arc welding (metal arc welding with covered electrode, SMAW)— 114 Self-shielded tubular-cored arc welding (FCAW-S)— 121 Submerged arc welding (SAW) with solid wire electrode— 122 Submerged arc welding (SAW) with strip electrode— 124 Submerged arc welding (SAW) with metal powder addition— 125 Submerged arc welding (SAW) with tubular cored electrode— 131 Metal inert gas welding (MIG, GMAW) with solid wire electrode— 132 Metal inert gas welding (MIG, FCAW-G) with flux cored electrode— 135 Metal active gas welding (MAG, GMAW) with solid wire electrode— 136 Metal active gas welding (MAG, FCAW-G) with flux cored electrode— 138 Metal active gas welding (MAG) with metal cored electrode— 141 Gas tungsten arc welding (TIG, GTAW) with solid filler material (wire/rod)— 15 Plasma arc welding.
1.6.2 For friction stir welding of aluminium, see ISO 25239.
1.6.3 Other processes and high heat input welding (> 50 kJ/cm) shall be specially approved.Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 39Fabrication and testing
DNV GL AS
2 Welding procedure specification
2.1 General
2.1.1 A WPS shall as a minimum contain the following information as relevant for the welding operation:
— identification of builder or subcontractor (name, address)— identification of the WPS and reference to the WPQR— welding process(es), including the order of processes if more than one process is used— number and configuration of electrodes for multi-wire welding— welding position(s) and direction of progression— joint type— backing and backing material— preheat and interpass temperatures— post-weld heat treatment details (temperature, time, etc.)— method of preparation including cleaning process— material: standard, grade and modification, delivery conditions (AR, N, NR, TM, QT), carbon equivalent(when relevant)
— nominal thickness or diameter range (dimensions)— welding consumables: trade name, electrode or wire diameter, shielding gas type, purity and flow rate,flux and recognised classification
— joint or groove design with tolerances of angles, root face and root gap. Throat thickness range for filletwelds
— welding sequence: number and order of passes or layers— electrical parameters: voltage range, current range, polarity, pulse welding details (machine settings and/or program selection)
— travel speed ranges— heat input ranges at least for root, fill and cap passes— details on cleaning processes employed and restrictions if any— minimum length of tack welds, when relevant— type and coating thickness of overweldable shop primer for fillet welding if automatic welding is applied.
2.1.2 The builder or subcontractor shall submit to the Society a preliminary welding procedure specification(pWPS) for review prior to the WPQT. The pWPS shall give all relevant parameters as required in [2.1.1].The pWPS may be modified and amended during the procedure welding as deemed necessary. In case thatthe test pieces welded according to the pWPS show unacceptable results, the pWPS shall be adjusted by thebuilder or subcontractor. The new pWPS shall be prepared and the test pieces shall be welded in accordancewith the new pWPS.
2.1.3 All relevant instruments for checking of welding parameters (e.g. temperature, ampere, volt) appliedfor the WPQT shall have valid calibration certificates and the adequacy of any control software shall bedocumented.
Guidance note:Calibration and validation in accordance with ISO 17662 are recommended.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
2.1.4 Qualification welding shall be performed under general conditions representative of the actual workingenvironment for the work shop site where the production welding will be performed.
2.1.5 The test results shall meet the specified minimum requirements given in this standard in order to bevalid for qualification of a WPS.
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 40Fabrication and testing
DNV GL AS
2.1.6 During qualification test welding, all welding parameters, (see [2.1.1]) and the weld bead width shallbe recorded for each welding pass. A report summarizing the records from the welding and the test results,i.e. a welding procedure qualification record (WPQR), shall be prepared. The WPQR shall give the materialcertificate of the base and filler materials applied in the WPQT.
2.1.7 Upon satisfactory completion of the required tests, the Society may approve the WPQR and thecorresponding WPS. The approval range shall be in compliance with the requirements given in [6].
2.2 Approval of welding procedure specification
2.2.1 WPS shall be approved by the Society prior to welding.
2.2.2 A WPS will be approved based on one of the following alternatives:
a) review of a WPQR corresponding to the WPS in question. The WPQT on which the WPQR is based shall bewitnessed by the Society or by a party recognized by the Society
b) review and verification of documentation showing successful application of the WPS over a prolongedperiod of time
c) the WPS is compiled on basis of other approved WPS.
2.2.3 For the following applications the approval of WPS shall be based on alternative [2.2.2] a):
— welds in aluminium— welds in cargo tanks, hull structure and process pressure vessel— welds in piping systems for liquified gases— welds in piping systems of ferritic-austenitic stainless steels— full and partial penetration welds in plate thickness above 50 mm— full and partial penetration welds for heat input more than 50 kJ/cm— full and partial penetration welds of material grade E and F— single run full or partial penetration welds— welds in the vertical down positions— welds between castings/forgings and rolled material, such as e.g. stern frames, rudder, rudder horns andstruts
— welds on grades VL D/E 47 steels for container vessels.
2.2.4 One or more WPS(s) may be prepared based on the data of one or more accepted WPQR(s) providedthe essential variables are kept within the acceptable limits. All limits and ranges for the applicable essentialvariables for the welding to be performed shall be stated in the WPS.
Guidance note:The number of WPQRs (alternative a) used for the preparation of a new WPS should not exceed 6. The number of WPSs(alternative c) used for the preparation of a new WPS should not exceed 3 where each of these 3 WPSs are approved by theSociety. When a new WPS is based on several WPQRs or WPSs the builder should prepare an overview indicating the overlap ofeach essential variable as specified in the Society's rules.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
2.2.5 For multi-process procedures the WPS approval shall be carried out by:
— separate WPQTs for each welding process, or— a multi-process procedure test. The approval of a multi-process procedure test is only valid for theprocess sequence carried out for the qualification test.
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 41Fabrication and testing
DNV GL AS
3 Welding procedure qualification test assembly and sampling oftest pieces
3.1 General
3.1.1 The base materials used for welding procedures shall be identified by means of material marking andcertificates. The material shall be certified with a VL or works (W) certificate. For definition of certificatetypes, see Pt.1 Ch.1 Sec.4 [2.1.1].
Guidance note:Requirements for impact toughness testing of base materials are given in Ch.2. Some welding procedures require impact testing atdifferent material thicknesses, e.g. centre of plate. Certification of the base materials according to Ch.2 do not necessarily requireimpact toughness testing of all material thickness positions relevant for welding. Where relevant, the purchaser is recommended toorder steel with adequate impact toughness at relevant plate thickness positions.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
Guidance note:For qualification of procedures for high heat input welding, the hull structural steels should be qualified accordingly for themaximum heat input.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
3.1.2 For welding procedure qualification tests of partial penetration welds, including partial penetration T-butt welds, the test conditions including all essential variables, test specimens and acceptance criteria shallbe agreed on a case by case basis with the Society.
3.2 Butt welds in plates
3.2.1 The test assembly shall consist of two plates welded together. For rolled plates, impact tested in thelongitudinal direction (KVL-tested, see Figure 1), the butt weld of the test assembly is perpendicular to therolling direction of the two plates. For extra high strength steel grades, impact tested in the transversedirection (KVT-tested, see Figure 1), the butt weld of the assembly is parallel to the rolling direction of thetwo plates.As far as possible the plates shall have a size which can simulate the heat transfer during the productionwelding. For manual or semiautomatic welding, a test assembly according to Figure 1 shall be carried outwith:wmin = 300 mmlmin = 350 mmFor automatic welding, the dimensions shall be:wmin = 400 mmlmin = 1000 mm
Guidance note:An increase of the minimum test piece length lmin may be needed if additional specimens like the round tensile test from the weldmetal are included.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
Edge preparation and fit-up shall be as detailed in the pWPS. The plates shall be joined and held by tackwelds to provide the correct gap for the edge preparation used. 50 mm of each end of the test piece shall bediscarded.
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 42Fabrication and testing
DNV GL AS
l min
Discard
wmin /2 wmin /2
Plate rollingdirection(steel platesKV -tested)
T
Plate rollingdirection(steel platesKV -tested)
L
50mm
50mm
Discard
Discard
Figure 1 Test assembly for butt welds in plates
3.2.2 The first fabrication welds shall be included as part of the welding procedure tests if:
— the test coupon for approval of WPS for fully mechanized or automatic welding process is not welded inthe comparable environment as the production condition or
— if the manufacturer has no or limited experience with the process and equipment.
For both cases the first fabrication welds shall be included as part of the welding procedure tests and besubjected to non-destructive testing.
3.2.3 The following mechanical tests are required from each assembly, see Figure 2:
— 2 tensile tests (flat specimen transverse to the weld)— 2 root and 2 face bend specimens shall be tested. For thickness 12 mm and over, 4 side bend specimensmay alternatively be tested
— at least 9 Charpy V-notch specimens with the notch location as given in [3.2.8]. Depending on the type ofjoint (one side or both side), the heat input and the plate thickness, more than 9 specimens are required
— 1 macrosection test (metallographic examination + hardness measurements)— 1 extra tensile test (round specimen from the weld metal) when the welding consumable is not typeapproved (see guidance note)
— specimens for transverse tensile testing shall be in accordance with Ch.1 Sec.3 [3.1.14]. Location offracture (WM or BM), and tensile strength shall be reported.Guidance note:Non-approved consumables may be accepted for qualification of a WPS. Consumables for production welding shall be approved bythe Society as required in Sec.1 [1.3].
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 43Fabrication and testing
DNV GL AS
Figure 2 Sampling of test specimens in plates
3.2.4 When round tensile test specimen is required, the specimen shall be machined to the dimensionsgiven in Ch.1 Sec.3 [3.1.14]. Care shall be taken so that the longitudinal axis coincides with the intersectionbetween the mid-plane of the weld, and the mid-plane of the plates. If the section area of the weld metal istoo small to allow sampling of the round specimen, an all-weld-metal tensile test shall be carried out.
3.2.5 Transverse side bend, root bend and face bend specimens shall be machined to the dimensions shownin Ch.1 Sec.3 [3.4]. For a butt joint between different material grades, the transverse bend test specimensmay be replaced by longitudinal bend test specimens. The test specimens shall be bent on a mandrel withdiameter 4 × t, where t is the thickness of the specimen.
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 44Fabrication and testing
DNV GL AS
Exceptions are for extra high strength steels with SMYS 420, 460, 500 for which the mandrel diameter shallbe 5 × t, and for steels levels 550, 620 and 690 for which the mandrel diameter shall be 6 × t. For extra highstrength steels with SMYS > 690 MPa, the mandrel diameter shall be agreed.The bending angle shall be minimum 180°.
3.2.6 The macro section shall include about 10 mm of unaffected base material and shall be prepared andetched on one side to clearly reveal the fusion line and the HAZ.
3.2.7 The hardness testing shall be in accordance with ISO 6507-1 and ISO 9015-1 or equivalent. This isonly required for grades with specified minimum yield strength 265 MPa and higher.Unless otherwise agreed, the Vickers method (HV10) is used.Indentations shall be made along traverses in the weld, HAZ and the parent metal; maximum 2 mm belowthe surface, see Figure 3. For each traverse, a minimum of 3 indentations shall be made in the weld, HAZ(both sides and with two additional indentations at a distance < 0.5 mm between the centre point of theindentation and the fusion line) and parent metal (both sides), see Figure 4.For HAZ the first indentation shall be placed as close to the fusion line as possible. For double sided welds,for fillet welds and T-, Y-, and K-joints, one additional row of indentations shall be made through the rootarea.For material grade VL D/E 47, one additional row of indentations shall be made from the mid-thickness of theplate.
Figure 3 Examples of hardness test with rows of indentations in butt welds
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 45Fabrication and testing
DNV GL AS
Figure 4 Example of hardness indentations in butt welds
3.2.8 The Charpy V-notch specimens shall be machined in accordance with the requirements given in Ch.1Sec.3 [3.3]. Three sets of three specimens each shall be sampled 1 - 2 mm below the surface of the parentmaterial and transverse to the weld. The V-notch shall be perpendicular to the plate surface.At least 9 Charpy V-notch specimens shall be localized in the welded joint as follows:
— 3 specimens with the notch along the weld metal centerline (WM)— 3 specimens with the notch in the fusion line (FL)— 3 specimens with the notch in the HAZ, 2 mm from the fusion line (FL+2)— Additional Charpy V-notch specimens with notch location(s) shall be tested as indicated in Figure 5, Figure6 and Table 3.
For a single- or double bevel groove preparation the location of the impact test specimens shall be takenfrom the vertical side of the groove (without the bevel).
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 46Fabrication and testing
DNV GL AS
Figure 5 Locations of V-notch for butt weld of normal heat input (heat input ≤ 50 kJ/cm)
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 47Fabrication and testing
DNV GL AS
Figure 6 Locations of V-notch for butt weld of high heat input (heat input > 50 kJ/cm)
Table 3 Notch location of Charpy V-notch impact test
Notch locationType of buttweld joint
Heat input[kJ/cm]
Plate thickness,t [mm] Cap Root
≤ 20 WM, FL, FL+2 -
20 < t ≤ 50 WM, FL, FL+2 WM≤ 50
> 50 WM, FL, FL+2 WM, FL
≤ 20 WM, FL, FL+2, FL+5 -50 < E ≤ 200
> 20 WM, FL, FL+2, FL+5 WM, FL, FL+2
One side
> 200 ≤ 20 WM, FL, FL+2, FL+5, FL+10 -
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 48Fabrication and testing
DNV GL AS
Notch locationType of buttweld joint
Heat input[kJ/cm]
Plate thickness,t [mm] Cap Root
> 20 WM, FL, FL+2, FL+5, FL+10 WM, FL, FL+2
≤ 50 WM, FL, FL+2 -≤ 50
> 50 WM, FL, FL+2 WM
≤ 50 WM, FL, FL+2, FL+5 -50 < E ≤ 200
> 50 WM, FL, FL+2, FL+5 WM, FL+2
≤ 50 WM, FL, FL+2, FL+5, FL+10 -
Both sides
> 200> 50 WM, FL, FL+2, FL+5, FL+10 WM, FL+2
3.2.9 For austenitic steels with service temperature above –105°C, HAZ impact test specimens are notrequired unless otherwise specified. For material thicknesses below 6 mm impact testing is not requiredunless specifically required by the Society or for cryogenic services where Pt.5 Ch.7 is applicable.Where multiple welding processes are qualified in a single test piece, impact test specimens shall be takenfrom the weld metal and HAZ that include each process. This does not apply to the process and consumablesused to make the first weld run or root deposit of a multipass weld.For dissimilar material grade and joints between cast or forged and rolled materials, impact tests shall becarried out on test specimens with notch in fusion line and 2 mm from fusion line in each parent material.
3.2.10 Where fracture mechanics testing (e.g. CTOD test) is required by the relevant rules, it shall be carriedout in accordance with Ch.1 Sec.3 [3.10]. Acceptance criteria are given in [5.7] and [8.2.3].When FM test is required for qualification of a welding procedure, testing of WM and GCHAZ shall be carriedout. Testing of BM is not required unless this is stated in the referring rule or standard. Fracture mechanicstesting of the base material, weld deposit or HAZ may be omitted based on a case-by-case approval. In thiscase, tests with satisfactory results shall have been carried out previously, by either the steel manufactureror the welding consumable manufacturer. This provided that the tested base material, weld deposit or HAZ isrepresentative.
3.3 Butt welds in pipes
3.3.1 The test assembly shall be in accordance with Figure 7.
Edge preparation and fit-up as detailed in the pWPS
D
aa
Figure 7 Test assembly for butt welds in pipes
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 49Fabrication and testing
DNV GL AS
a = minimum value 150 mmD = outside diameter.
Guidance note:The word 'pipe', alone or in combination, is used to mean 'pipe', 'tube' or 'hollow section'.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
3.3.2 The following mechanical tests are required from each assembly, see Figure 8:
— two (2) tensile test (flat specimen transverse to the weld)— two (2) root and two (2) face bend specimens shall be tested. For thickness 12 mm and over, alternativelyfour (4) side bend specimens may be tested
— three (3) sets of three (3) Charpy V-notch specimens with the notch location as given in [3.2.8]— for pipe thickness > 20 mm with one side welding, one additional set of specimens shall be taken from theroot area as given in [3.2.8]
— one (1) macro section test (metallographic examination + hardness measurements).
Figure 8 Sampling of test specimens in pipes
3.4 Full penetration TKY joints for plates
3.4.1 WPQT's for full penetration groove welds between plates at right angles or inclined, i.e. T- or K- or Y-configurations, shall cover a weld length of minimum 350 mm, see Figure 9. The test assembly shall considerthe rolling direction, as for the butt welds, see [3.2.1].
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 50Fabrication and testing
DNV GL AS
Figure 9 Test assembly for full penetration T-joints
a = 3 t; minimum value 150 mmb = 6 t; minimum value 350 mm
3.4.2 The following mechanical tests are required from each assembly, see Figure 10:
— 3 sets of Charpy V-notch tests with the notch location as given in [3.2.8], see guidance note— for web plate thickness > 20 mm with one side welding, one additional set of specimens shall be takenfrom the root area as given in [3.2.8], see guidance note
— 1 macrosection test (metallographic examination + hardness measurements).Guidance note:If the flange thickness is < 30 mm and therefore Charpy V-notch specimens can't be machined, qualification tests on butt weldsmay be performed as an alternative. In this case, with comparable welding parameters as for the full penetration T-joint.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
3.4.3 Tests as detailed do not provide information on the tensile strength of the joint. Where the tensilestrength properties are relevant for the application an additional butt weld qualification shall be performedusing the same welding parameters.
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 51Fabrication and testing
DNV GL AS
Figure 10 Sampling of test specimens in full penetration T-joints
3.5 Branch connection
3.5.1 The following mechanical tests are required from each assembly, see Figure 11:
— Three (3) sets of Charpy V-notch tests sampled at 9 o'clock in the branch pipe and with the notch locationas given in [3.2.8].
— For pipe thickness > 20 mm with one side welding, one additional set of specimens shall be taken fromthe root area as given in [3.2.8]. Alternatively, the tests may be carried out on test specimens from arepresentative butt weld assembly.
— Two (2) macrosection tests (metallographic examination + hardness measurements), one at 12 and oneat 6 o'clock.
3.5.2 For joint configuration involving acute angles (less than 15°), restrictions and testing should bespecified and accepted by the Society prior to qualification.
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 52Fabrication and testing
DNV GL AS
Figure 11 Test assembly for branch connections
a = minimum value 150 mmD1 = outside diameter of the main pipet1 = wall thickness of the main pipeD2 = outside diameter of the branch pipet2 = wall thickness of the branch pipeα = branch connection angle.
3.6 Fillet welds
3.6.1 For fillet welds, the two plates are assembled and positioned edgewise so as to constitute a tee-assembly with no clearance. For plate fillet welds, the test assembly shall be as defined in Figure 12, exceptfor vertical-down fillet welds on structural steel grades A to F40. For vertical-down fillet welds the testassembly shall be as defined in Figure 13 or Figure 14. For pipe fillet welds the test assembly shall be asdefined in Figure 15.
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 53Fabrication and testing
DNV GL AS
For manual and semi-automatic welding the length of the test piece shall be:
Lmin = 350 mm
For automatic welding the length shall be:
Lmin = 1000 mm
Figure 12 Test assembly for plate fillet welds
Figure 13 Double T- joint (cruciform) plate test piece for manual and semi-automatic weldingprocedures
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 54Fabrication and testing
DNV GL AS
Figure 14 Double T- joint (cruciform) plate test piece for automatic welding procedures
Figure 15 Test assembly for pipe fillet welds
Weld and fit-up shall be as detailed in the pWPS. The test assembly shall be welded on one side only.However, for automatic two side fillet welding (tandem technique), welding from two sides is acceptable. Forsingle run manual and semi-automatic welding, the stop/restart position shall be included in the test lengthunless otherwise agreed, and shall be clearly marked for subsequent examination. The ends of the specimenare exempted from examination over a length of 50 mm.When the automatic fillet welding procedure is intended for plates and sections coated with overweldableshop primer, similarly coated plates shall be used for the qualification. The type of the shop primer and thedry film thickness shall be recorded in the WPQR.
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 55Fabrication and testing
DNV GL AS
3.6.2 The following destructive tests shall be performed:
— Two macrosection tests (metallographic examination, hardness measurements on one macrosection takenfrom the weld start of the test assembly).For single run manual and semi-automatic welding, one of themacrosections shall be taken at the marked position of the stop/restart, for more details see [3.2.6]. Forhardness testing, see Figure 16, Figure 17 and [3.2.7].
— For plate fillet welds: one fracture test shall be performed by folding the upright plate onto the throughplate, e.g. according to ISO 9017. Evaluation shall be concentrated on cracks, porosity and pores,inclusions, lack of fusion and incomplete penetration. Imperfections that are detected shall be assessed inaccordance with EN ISO 5817 quality level B.
— Pipe fillet welds: one additional macrosection test.
Unless cruciform tensile tests are carried out, the tests as detailed in [3.6], do not provide information on themechanical properties of the joint. Where these properties are relevant for the application, an additional buttweld qualification shall be performed using the same welding parameters.When the shop primer is not approved, see Sec.6 [3], extra testing according to DNVGL-CP-0109 is required.
Figure 16 Examples of hardness test with row indentation (R) in fillet welds and in T-joint welds
Figure 17 Example showing the position of the indentations for hardness test in the weld metal,the heat affected zone and the base metal of a fillet weld (dimensions in [mm])
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 56Fabrication and testing
DNV GL AS
3.6.3 Qualification of cruciform joints is required for vertical-down fillet welding on hull structure steel gradesA to F40. For the test assembly see Figure 13 and Figure 14.The throat thickness of the fillet for the cruciform test piece shall correspond to those used in production, butshall not exceed 0.5 times the plate thickness of the test piece.For the set of double-T (cruciform) test specimens see Figure 18 and for the calculation of the shear tensilestrength see Figure 19.The cruciform tensile test specimens shall be evaluated in order to determine the tensile-shear strengthof the weld metal according to Figure 19. Before the performance of cruciform tensile tests, the fillet weldthroat thicknesses and the width of the specimens shall be measured. The width of the specimen should beabout 35 mm.For the tensile-shear strength requirements see Table 6.The following destructive tests shall be performed in addition to [3.6.2]:
— three cruciform tensile test specimens (Z)
M = macro sectionZ = cruciform tensile test specimen
Figure 18 Set of double-T (cruciform) test specimens
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 57Fabrication and testing
DNV GL AS
Figure 19 Cruciform tensile test specimen (weld cross section)
3.6.4 WPQTs of pipe fillet welds and corresponding WPS shall be in accordance with an internationalrecognized standard. Test assembly is shown in Figure 15.
4 Non-destructive testing of test assemblies
4.1 Full penetration butt joints and T-, K-, and Y-joints
4.1.1 The extent of the testing shall be as follows:
— 100% visual testing (VT)— 100% radiographic testing (RT) or ultrasonic testing (UT)— 100% surface crack detection (magnetic particle testing (MT) for ferromagnetic materials or penetranttesting (PT) for non-ferromagnetic materials).
Acceptance criteria: the soundness of the weld shall comply, unless otherwise specified, with EN ISO 5817quality level B, except for undercut, excess weld metal, incorrect weld toe and excess penetration for whichlevel C applies. Regarding use of EN ISO 5817 and EN ISO 10042 for RT, UT, MT and PT, EN ISO 17635 shallbe followed.
Guidance note:For ultrasonic testing, level 2 of ISO 11666 is considered equal to level B of EN ISO 5817.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
4.2 Fillet welds and partial penetration welds
4.2.1 The extent of testing shall be as follows:
— 100% VT— 100% surface crack detection (MT for ferromagnetic materials or PT for non-ferromagnetic materials).
Acceptance criteria: the soundness of the weld shall comply, unless otherwise specified, with EN ISO 5817quality level B, except for undercut, incorrect weld toe, excessive convexity and excessive throat thicknessfor which level C applies. If the stop/restart spot is included in the test length, special attention shall be paid
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 58Fabrication and testing
DNV GL AS
to this position with respect to profile, proper fusion and absence of crater defects. Regarding use of EN ISO5817 and EN ISO 10042 for MT and PT, EN ISO 17635 shall be followed.
5 Acceptance criteria of mechanical testing
5.1 Transverse tensile test
5.1.1 The tensile strength shall not be below the specified minimum tensile strength for the material grade inquestion. Location of fracture (WM or BM), and tensile strength shall be reported.
5.2 Bend test
5.2.1 After bending, the test specimens shall not reveal any open defects in any direction greater than 3mm, except for defects appearing at the corners (edges) of a test specimen during testing where longerdefects may be accepted by the Society subject to case by case evaluation, see [5.2.2].
Guidance note:Where a bend test specimen reveal several open discontinuities on the convex side of the specimen after bending, the rules do notspecify acceptance criteria. If the sum of the length of all discontinuities with size in the range 1 mm to 3 mm do not exceed 10mm in total, this is usually considered acceptable. If total length is more than 10 mm, it is advised to do a re-test or to investigatethe root cause.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
5.2.2 Corner cracks with length greater than 3 mm may be accepted subject to investigation and evaluationof root cause. Corner cracks greater than 3 mm and originating from fusion type discontinuities (e.g. slaginclusion or lack of fusion) are not accepted. Other corner cracks with length less than 6 mm are accepted.
5.3 Macrosection and hardness testing5.3.1 MacrosectionCracks and lack of fusion are not accepted. Other defects shall follow Level B of EN ISO 5817. The weldedjoints shall have a regular profile with smooth transitions to the base materials and without significant orexcessive reinforcement. Acceptance criteria for weld profile according to IACS Rec. No. 47.
5.3.2 Hardness test
— for material grades up to and including VL 420 a maximum hardness limit of 350 HV10 shall be met,except for single run fillet welds where the maximum hardness limit shall be 380 HV10
— for VL460 VL 500, VL 550, VL 620 and VL 690 grades the maximum hardness limit shall be 420 HV10— for VL 890 and VL 960, the maximum hardness limit shall be 450 HV10.
5.4 Impact testing
5.4.1 For rolled steels for structural application, the test temperature and absorbed energy shall be inaccordance with the following requirements:
Table 4 Impact test temperature
Impact test temperatures Grades
+20°C A, A27S, A32, A36 and A40
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 59Fabrication and testing
DNV GL AS
Impact test temperatures Grades
0°C B, D, D27S, D32, D36 and D40
–20°C E, E27S, E32, E36 and E40
–40°C F27S, F32, F36 and F40
The average value for absorbed energy in WM, FL and HAZ shall not be less than:
— for grades VL A and VL B, all welding methods and positions: 27 J.
For all other grades given above:
— for manual and semi-automatic welding in all welding positions except vertical: 47 J— for automatic welding and fully mechanised welding: 34 J (for VL 40 grades:39 J)— for manual and semi-automatic welding in vertical position: 34 J (for VL 40 grades: 39 J).
For multi-pass increased toughness welds of high strength structural steels acc. to Pt.5 Ch.2 Sec.10 [2.2.5]the Charpy V-notch test temperature and the average value for absorbed energy in weld metal, fusion lineand HAZ shall be the same as required for the base material.The same applies for the notch locations which shall be tested additionally:
— mid-thickness (t/2): WM, FL, FL+2, FL+5— root, provided root is not at mid-thickness: WM, FL, FL+2, FL+5.For extra high strength structural steels (except D/E 47, see [7.1.4]), the Charpy V-notch test temperatureand the average value for absorbed energy in weld metal, fusion line and HAZ shall be the same as requiredfor the base material.
5.4.2 For boiler and pressure vessel steels (Ch.2 Sec.3 [2]), pipes for pressure system (Ch.2 Sec.5 [2])and weldable C- and C-Mn steel forgings and castings (Ch.2 Sec.6 and Ch.2 Sec.8), the Charpy V-notch testtemperature and the average value for absorbed energy in weld metal, fusion line and HAZ shall be the sameas required for the base material.For C-, C-Mn and nickel alloy steels for liquefied gas systems, see [9.2].For austenitic-ferritic stainless steels, see [10.1], and for austenitic steels, see [11.2].
5.4.3 The average impact requirements shall be satisfied for each notch location. One single value ofthe three values from each notch location may be below the average requirement, but not below 70% ofminimum average.
5.4.4 In the case of reduced Charpy V-notch test specimens (10 x 7.5 mm and 10 x 5 mm); the impactenergy values to be obtained shall satisfy Table 5.
Table 5 Impact energy requirement for subsize specimens
Dimensions of Charpy V-notch test specimen [mm] Impact energy
10 × 10 1 × KV
10 × 7.5 5/6 × KV
10 × 5 2/3 × KV
5.4.5 Where the results from a set of three impact test specimens do not comply with the requirements,an additional set of three impact test specimens may be taken. The results obtained shall be combined withthe original results to form a new average which, for acceptance, shall be not less than the required value.Additionally, for these combined results not more than two individual values shall be less than the requiredaverage value. Of these, not more than one shall be less than 70% of the required average value.
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 60Fabrication and testing
DNV GL AS
5.5 Cruciform joint tensile-shear strength
5.5.1 For the tensile-shear strength requirements applicable to cruciform tensile specimens, see Table 6.
Table 6 Requirements applicable to cruciform tensile specimens
Grades Tensile-shear strength [N/mm2]
A – E, A27S - F27S 350
A32 – F36 430
A40 – F40 450
5.6 Welds between different material grades
5.6.1 When a butt weld is made between two steels of different grade, the test temperature and achievedimpact energy shall comply with the minimum specified requirements for the lower grade, see [5.4.1] and[5.4.3]. The tensile strength shall meet the requirements of the steel having the lower strength. The validityof the corresponding WPS shall be limited to the range qualified by the lower steel grade welded to a steellimited by the range qualified by the higher grade.
Guidance note:As an example the test temperature, impact energy and tensile strength for the butt welded joints given in Figure 20 are thoserequired for the plate of grade D in the left assembly and for the plate of grade E in the right assembly.As an example for the qualified range of steels, the left assembly qualifies welding of steel grades A - D welded to steel grades A- E. Welding of grade E to E is not covered. For the right assembly welding of steel grades A - E welded to steel grades A - EH iscovered. Welding of AH - EH welded to AH - EH is not covered.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
grade Egrade D
grade E grade EH
Figure 20 Butt welded plate joints of different grades
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 61Fabrication and testing
DNV GL AS
5.7 Fracture mechanics test
5.7.1 The critical CTOD for all of the specimens shall be equal to or larger than 0.15 mm unless otherwisespecified by the relevant rules. For D/E 47 grades and COD grades, see [8.2.3].
5.7.2 If, for HAZ or weld deposit, one or more of the three specimens have a critical CTOD lower than 0.15mm additional tests may be carried out. In such a case the characteristic value, as defined in Table 7, shallbe equal to or larger than 0.15 mm.
Table 7 Characteristic value of CTOD
Number of valid tests 1) Characteristic value
3 to 5 Lowest result
6 to 10 Second lowest result
11 to 15 Third lowest result
1) All valid tests that have been carried out shall be included in the evaluation. It is not permissible to discard any validtest result.
5.7.3 If the characteristic value as specified in Table 7 is lower than 0.15 mm an ECA (engineering criticalassessment) may be carried out with the purpose of demonstrating that extra capacity is available in thestructure. Acceptance based on ECA shall be approved.
5.8 Retesting
5.8.1 If the WPQT fails to comply with any of the requirements for NDT one extra WPQT may be welded andsubjected to the same testing. If this additional test does not meet the relevant requirements, the actualpWPS shall be considered as not qualified and a re-specification of the pWPS shall be made prior to a newqualification test.If the result of any destructive test fails to meet the requirements, two further tests may be made from thesame welded joint if there is sufficient material available. If not, a new assembly may be welded using thesame WPS. If either of these additional test specimens does not comply with the relevant requirements, theWPS shall be regarded as not capable to comply with the requirements without modification.
6 Validity of approved welding procedures
6.1 General
6.1.1 The validity of an approved WPS is restricted to the builder/subcontractor receiving the approval.This includes yards/subcontractors under the same technical management and working in accordance withthe same QA system and procedures. Builder’s WPS may be transferred to and used by a subcontractor,provided the principles of ISO 3834-2 and ISO 14731 are implemented. This shall be documented by theyard/subcontractor and accepted by the Society. For this case WPT or extended NDT may be required by theSociety.
6.1.2 Qualification of a WPS remains valid provided the specified welding parameters are kept within thequalified ranges during production welding. The qualified ranges are given in [6.2]. If one or more of theWPS specified welding parameters are outside the qualified ranges during production, the WPS shall be re-specified and re-qualified.
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 62Fabrication and testing
DNV GL AS
6.2 Range of qualification
6.2.1 A qualified WPS shall be used within the ranges of the parameters of essential variables listed below.
6.2.2 Base materialEssential parameters for the base material:
a) The following changes and considerations shall lead to a new qualification. Significant change of materialproperties which obviously will affect the weldability and mechanical properties, such as:
— change from wrought (rolled, forged) steel to cast steel or vice versa (applicable also for stainlesssteels)
— change from delivery condition quenched and tempered (QT) to any other delivery condition or viceversa, applicable for forgings, castings, and extra high strength hull structural steel grades
— changes in chemical composition which will obviously affect the weldability, and in particular:
— for steels with C ≥ 0.22 or Ceq ≥ 0.45 the WPQT on which the WPS is based, should be qualified ona base material having a Ceq not less than 0.03 of the material to be welded
Guidance note:Example: WPQT for a material with actual Ceq = 0.50 may be qualified on a material with Ceq ≥ 0.47.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
— BCA steel grades with chemical composition outside the limitations of Ch.2 Sec.2 Table 9 and Ch.2Sec.2 Table 14 shall follow the requirements of [8.3.1].
b) Changes related to strength levels and toughness grades for rolled steel plates that require newqualification:
— for normal and high strength steels see Ch.2 Sec.2, WPQTs are considered applicable to the same andtwo lower strength levels as that tested (the special grade VL 27S is not counted, e.g. qualification ofVL A36 may also qualify welding of grades VL A, VL A27S and VL A32)
— for extra high strength steels, WPQTs are considered applicable to the same and one lower strengthlevel as that tested. Examples:
— qualification of grade VL A500 will qualify grade VL A460— qualification of grade VL E420 will qualify grades VL A420 to VL E420 and VL A40 to VL E40
— for high heat input welding processes (> 50 kJ/cm), the WPQT is applicable to the toughness gradetested and one strength level below, e.g. qualification of grade VL E40-W200 will qualify grades VLE40-W200 and VL E36-W200
— the qualification of steel grades of higher toughness requirements will qualify the grades of lowertoughness but not vice versa, e.g. qualification of grade VL E will also qualify grades VL A, VL B andVL D.
c) Changes related to strength levels and toughness grades for castings and forgings that require newqualification:
— change to a grade of higher specified strength— change to higher specified toughness requirements. That is: lower impact toughness temperaturerequirements or higher impact toughness value requirements.
d) For welding with heat input more than 50 kJ/cm:
— for TM steels not pre-qualified for high heat input welding: change of material manufacturer requireseither new qualification, or special case by case approval. For case by case approval, the followinginformation shall be submitted for the TM steels in question: grade, thickness range, deoxidationpractice, fine grain practice, aim range of chemical composition, aim maximum Ceq and Pcm, weldingproduction test results, etc.
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 63Fabrication and testing
DNV GL AS
e) For welding where CTOD properties are required for the weld:
— parameters affecting the CTOD properties shall be specified and controlled, e.g. chemical compositionof base material, carbon equivalent (Ceq or Pcm), heat input, welding consumables, etc. The relevantparameters to be controlled shall be specified on the WPS.
Guidance note:The specification for chemical composition of base materials may typically give ranges of each element as indicatedin EN 10225 Option 18 or API RP2Z, under the provision that the chemical composition range is also within the rulerequirements given for the corresponding grade.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
6.2.3 ThicknessThickness t is defined as follows:
a) butt welds:
— the base metal thickness, which for welds between dissimilar thicknesses is that of the thinnermaterial
b) T-joints in plate:
— the thickness of the plate with bevelling (abutting member)c) fillet weld:
— the thickness of both base materialsd) for a set-on branch connection:
— the thickness of the branch pipee) for a set-in or set-through branch connection:
— the thickness of the main pipef) for partial penetration welds:
— same as for butt weld or T-joint, respectively.
The requirements for qualified thickness range shall be as given in Table 8. This table is applicable to fullpenetration butt welds in plates, pipes and T-, Y-, K-joints, fillet welds and partial penetration welds.
Table 8 Qualified thickness range
Qualification range [mm] 1, 2, 3)Thickness of test piece,
t [mm] Single run, or singlerun from both sides Multi-run and all fillet welds 4, 5, 6)
t ≤ 3 0.7 × t to 1.3 × t 0.7 × t to 2 × t
3 < t ≤ 12 0.7 × t to 1.1 × t 3 mm to 2 × t
12 < t ≤ 100 0.7 × t to 1.1 × t 7) 0.5 × t to 2 × t 8)
t > 100 Not applicable 50 mm to 2 × t 8)Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 64Fabrication and testing
DNV GL AS
Qualification range [mm] 1, 2, 3)Thickness of test piece,
t [mm] Single run, or singlerun from both sides Multi-run and all fillet welds 4, 5, 6)
1) the maximum thickness qualified for vertical downward welding is 1.0 × t2) for multi process procedures, the recorded thickness contribution of each process shall be used as basis for the
range of approval for the individual welding process3) the approval of maximum thickness of base metal for any technique shall be restricted to the thickness of test
assembly if three of the hardness values in the heat affected zone are found to be within 25 HV of the maximumpermitted, as stated in [5.3.2]
4) where a fillet weld is qualified by a butt weld qualification, the throat thickness range qualified shall be the same asthe qualified plate thickness range
5) for fillet welds between materials of dissimilar thickness, the qualified thickness range shall be applied to bothparent materials independently. Example: Multi-run fillet weld. Thickness of abutting member is 15 mm, thicknessof base plate is 25 mm and throat thickness is 15mm by multi-run. Qualified range for abutting member is then 7.5mm to 30 mm, qualified range for base plate is 12.5 mm to 50 mm. Qualified throat thickness “a” range is 7.5 mmto 30 mm
6) for fillet welds on castings and forgings, qualification of thickness ≥ 30 mm will qualify unlimited maximumthickness
7) for high heat input processes > 50 kJ/cm, the upper limit of range of validity is 1.0 × t8) where fracture mechanics test (CTOD) is required, qualified thickness range is 0.5 × t to 1.1 × t.
In addition to the requirements of Table 8, the range of approval of throat thickness 'a' for fillet welds shallbe as follows:
— single run: '0.75 × a' to '1.5 × a'— multi-run: same qualification range as for thickness (t) of multi-run butt welds, i.e. t = a, see Table 8.
6.2.4 Diameter of pipes and branch connectionsThe qualification of a WPQT on diameter D shall include qualification for diameters in the following ranges asgiven in Table 9.
Table 9 Qualified range for pipe and branch connection diameters
Diameter of the test piece,
D [mm] 1, 2)Qualification range [mm]
D ≤ 25 0.5 × D to 2 × D
D > 25 > 0.5 × D and plates
1) D is the outside diameter of the pipe or outside diameter of the branch pipe2) qualification given for plates also covers pipes when the outside diameter is greater than 500 mm.
6.2.5 Angle of branch connectionsA WPQT carried out on a branch connection with angle α shall qualify all branch connection angles in therange of α to 90°.
6.2.6 Welding consumablesThe following changes shall lead to a new qualification:
— any change in consumable classifications: mechanical properties, type of covering core or flux (e.g. basic,rutile), nominal chemical composition and increase in hydrogen content
— change of consumable brand when impact testing for WPQT is required at temperatures below –20°C— change of welding consumable brand for high heat input welding (> 50 kJ/cm)
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 65Fabrication and testing
DNV GL AS
— any significant change of mixture/composition, see Sec.4 Table 8, flow rate, filling time and filling volumefor shielding and purging gases
— change of consumable brand for COD steels.
6.2.7 Welding positionsThe following changes shall lead to a new qualification:
— change from one principal welding position to another, unless complying with Table 13. Welding positionsare indicated in Figure 21, Figure 22 and Figure 23.
1G (PA) FLAT
3G (PF-UPWARDSPG-DOWNWARDS)
VERTICAL
2G (PC) HORIZONTAL -VERTICAL
4G PE) OVERHEAD
Figure 21 Plate test positions
Figure 22 Pipe test positions
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 66Fabrication and testing
DNV GL AS
THROAT OF WELDVERTICAL
AXIS OF WELDHORIZONTAL
AXIS OF WELDHORIZONTAL
Note : One pla te mus t be ho rizon ta lHORIZONTAL POSITION 2F (PB)
FLAT POSITION 1F (PA)
AXIS OF WELD VERTICAL
AXIS OF WELDHORIZONTAL
Note : One pla te mus t be ho rizon ta lOVERHEAD POSITION 4F (PD)
VERTICAL POSITION 3F(PF-UPWARDSPG-DOWNWARDS)
Figure 23 Positions of test plate for fillet welds
6.2.8 Type of jointThe following changes shall lead to a new qualification:
a) change from fillet weld to butt weldb) change from butt weld to fillet weld in case of automatic welding of fillet joint with shop primerc) change from T-, K- or Y-joint to butt weld but not vice versa, see also Table 13 note 2)d) change from butt joint in plates to butt joints in pipes with outside diameter less than 500 mme) changes outside the qualification ranges given in Table 10
Table 10 Qualified ranges for one and two-side butt welds with or without backing/gouging
Type of welded joint for test assembly Range of approval
With backing A A, COne side
Without backing B A, B, C, D
With gouging C CButt welding
Both SideWithout gouging D C, D
f) any change of groove angle outside the limits given in Table 11
Table 11 Tolerances for groove angle of butt welds, based on groove angle qualified by WPQT
Groove angle β(°) from WPQT Qualified tolerances β [°]
β < 35 -0, +20
35≤ β < 40 Min. 35, +20
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 67Fabrication and testing
DNV GL AS
Groove angle β(°) from WPQT Qualified tolerances β [°]
β ≥ 40 -5, +20
g) any change of root gap outside the limits given in Table 12. Different gaps and tolerances may beapproved based on adequate qualification.
Table 12 Tolerances for root gap of butt welds, based on root gap qualified by WPQT
Root gap [mm]1)Backing Welding method
Standard Max. Tolerances
With backing All 3 - 10 16 -2, +6
Manual,semi-automatic
3 5 ±2Without backing
Automatic 0.8 2 -0.8, +1.2
1) welding gap of more than 16 mm is for remedial welding. See also [1.5].
6.2.9 Welding conditionThe following changes shall lead to a new qualification:
— any change of welding process— any decrease in preheat temperature— higher interpass temperature than that used in the qualification test— change of post weld heat treatment parameters used in the qualification test. Holding time may beadjusted as a function of thickness
— change from multi-pass welding to one-pass welding— change in welding current from A.C. to D.C. or vice versa, or change in polarity. If recommended by thewelding consumable manufacturer a case by case exemption may be given for SMAW in change from A.C.to D.C.
— change in metal powder or wire addition beyond ±10%— change from manual (or semi-automatic) to fully mechanized (or fully automatic welding processes), andvice versa, see [1.6.1]
— change in heat input beyond ±25% or 55 kJ/cm maximum heat input, whichever is smaller. For high heatinput welding (> 50 kJ/cm) and/or for material with SMYS equal to or above 420 MPa the change shall notbe more than +10/-25%. The heat input range shall be established at least for (1) root pass and (2) fillingand cap passes.
Guidance note:Average heat input for the relevant welding passes (root, fill, cap) is calculated based on the recorded values from the WPQT.The qualified range (±25% or +10/-25% as relevant) is based on the calculated average value.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
— change of consumable brand for processes with heat input more than 50 kJ/cm.Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 68Fabrication and testing
DNV GL AS
Table 13 Qualified principal positions for butt welds and fillet welds, steel
Qualified positions 3)
Butt welds Fillet weldsTest weld
jointconfiguration1,2)
Principlepositions
Plates Pipes Plates Pipes
Butt welds in plates
2G + 3G4)
1G
2G
3G
4G
All
1G
2G
3G
4G
-
-
-
-
-
All
1F
2F
3F
4F
All
1F
1F, 2F, 4F
3F
1F, 4F
Butt welds in pipes
2G + 5G = 6G
1G
2G
5G
All
1G
2G
All
All
1G
1G, 2G
1G, 5G
All
1F
2F
All
All
1F
1F, 2F, 4F
All
Fillet welds
2F + 3F4)
1F
2F
3F
4F
5F
-
-
-
-
-
-
-
-
-
-
-
-
All
1F
2F
3F
4F
All
All
1F
1F, 2F, 4F
3F
1F, 2F, 4F
All
1) pipes with D > 500 mm are considered equivalent to plates (apply only to the main pipe in branch connections)2) branch connections shall be qualified separately3) the vertical downwards position shall be qualified separately4) one test assembly for each principle position.
7 Additional requirements for welding procedure qualification testof VL D/E47
7.1 Test requirements
7.1.1 These requirements shall be applied for all VL D/E47 with or without suffix BCA, COD or BCACODincluding those with additional suffixes, e.g. E47Z35BCACOD.
7.1.2 The butt weld tensile strength shall not be less than 570 N/mm2. The position of fracture shall bereported.
7.1.3 The bending mandrel diameter shall be 5 × t and the bending angle shall be minimum 180°.
7.1.4 Charpy V-notch test results shall satisfy a minimum average requirement of 64J when tested at -20°C.For grade BCA, COD and BCACOD plates with thickness t > 50 mm, Charpy V-notch impact toughness testingis required for the following additional notch locations:
1) mid-thickness (t/2): WM, FL, FL+2, FL+52) root, provided root is not at mid-thickness: WM, FL, FL+2, FL+5.
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 69Fabrication and testing
DNV GL AS
7.1.5 The maximum hardness limit shall be 380 HV10.
7.1.6 The COD grades shall additionally satisfy the requirements of [8].
8 Additional requirements for welding procedure qualification testof all COD grades
8.1 General
8.1.1 These additional requirements shall be applied for WPQT of the following steel grades:
— all VL D36 and E36; grades with the suffix COD— all VL D40 and E40; grades with the suffix COD— all VL D47Z35COD and E47Z35COD, including those with additional suffixes, e.g. E47Z35BCACOD.
8.2 Welds in plates
8.2.1 Test assembly shall be as described in [3.2.1] and [3.2.2]. The WPQT plate thickness for CTOD testshall be the maximum production plate thickness, if not otherwise agreed.
8.2.2 For charpy v-notch impact toughness testing for plate thickness t > 50 mm, the following additionalnotch locations shall be tested:
1) mid-thickness (t/2): WM, FL, FL+2, FL+52) root, provided root is not at mid-thickness: WM, FL, FL+2, FL+5.
8.2.3 CTOD testing procedure and the specimens for CTOD testing shall be in accordance with Ch.1 Sec.3[3.10].One set of CTOD specimens is required for each of the notch locations given below for each test assembly:
— GCHAZ— weld metal.
CTOD testing shall be carried out at –10°C or design temperature, whichever is lower.Minimum single CTOD value of 0.18 mm and minimum average CTOD value of 0.20 mm for notch position inGCHAZ and weld metal shall be fulfilled. The average CTOD is calculated as average of three valid CTOD testresults.Provided the CTOD requirements are already qualified, e.g. during the approval of manufacturer test for therelevant essential welding parameters, then the applicable CTOD testing need not to be repeated. For thiscase, a new WPS may be prepared based on the WPQR established by manufacturer for qualification of theCOD steel. In addition to the limitations to the validity given by [6], the limitations given by [8.3] do alsoapply.
Guidance note:The required CTOD testing of the weld metal (i.e. for qualification of the welding consumables) is not commonly covered by theapproval of manufacturer test of COD grade steel. Each welding consumable type and grade from each consumable manufacturershall be qualified as relevant. A welding consumable qualified on one grade of COD steel may be used on COD steels from othersteel manufacturer, provided the chemical composition range of the COD steel (as specified by the steel manufacturer) comply withthe rule requirements for chemical composition of the corresponding steel grade without COD.Essential parameters relevant for qualification of welding for COD steels may not be the same as the general essential parametersfor WPS. Parameters affecting the CTOD properties should be considered as essential in this respect, e.g. heat input is an essentialparameter for CTOD properties of HAZ, while welding method is not.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 70Fabrication and testing
DNV GL AS
8.3 Further limitations to the range of qualification
8.3.1 The carbon equivalent shall not exceed (to be stated on the WPS):
— max. Ceq = Ceq(tested base material) + 0.03%— max. Pcm = Pcm(tested base material) + 0.02%.
See also [6.2.2].
8.3.2 The maximum thickness qualified is 1.0 x t, where t is the thickness of the tested plate, unlessotherwise approved.
9 Additional requirements for welding procedure qualification testfor liquefied gas systems
9.1 General
9.1.1 The general requirements are given in Pt.5 Ch.7 Sec.6. Other mandatory requirements, e.g. IGC code,shall be observed in addition, if more stringent.
9.2 Welds in plates and pipes
9.2.1 Test assembly shall be as described in [3.2.1] or [3.3.1]. For butt welds in plates the test assembliesshall be prepared so that the rolling direction is parallel to the direction of welding.
9.2.2 For carbon, carbon-manganese and low alloy steels.From each test assembly for plates the Charpy-V-notch impact toughness test specimen locations shall be asfollows (replacing those given in [3.2.1] and [3.3.1]):One set of Charpy V-notch test specimens (each set consists of 3 specimens) with the notch location asfollows:
— weld centerline— fusion line— 1 mm, 3 mm and 5 mm from the fusion line (HAZ).
Charpy V-notch testing shall be conducted at the temperature prescribed for the base material.
9.2.3 For austenitic steels:Charpy V-notch test specimens are required for design temperature below –105°C. Tests shall be carried outat -196°C unless otherwise agreed, with notch location at weld centerline.
9.3 Test requirements
9.3.1 The butt weld tensile test shall comply with the following requirements:
— generally, the tensile strength shall not be less than the specified minimum tensile strength for the parentmaterial. In cases where the Society has approved the use of welding consumables which give lowertensile strength in the weld metal than that required for the parent material, the approved value for thewelding consumable in question applies. The position of fracture shall be reported.
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 71Fabrication and testing
DNV GL AS
9.3.2 Charpy V-notch testing shall be conducted at the temperature prescribed for the base material. Whenspecimens of 10 × 10 cross-section are used, the average value from 3 tests shall not be less than 27 J forweld metal. One single test may give a value below the required average but not lower than 19 J.For fusion line and heat affected zone the requirement for minimum average value is the same as for thebase material.
9.4 Weld production test (WPT) requirements
9.4.1 The test requirements shall comply with [9.1] and [9.2].
9.4.2 Impact testing for carbon-manganese steels, austenitic steels and nickel steels shall be conducted atthe temperature prescribed for the base material. For austenitic steels, testing are only required for designtemperature below –105°C. For welding of plates the following apply when pieces of 10 × 10 mm crosssection are used:
a) If the impact test pieces from plate materials are taken with their longitudinal axes transverse to themain direction of rolling, the average value from 3 tests shall not be less than 27 J for weld metal,fusion line, heat affected zone and parent material. One single test may give a value below the requiredaverage, but not lower than 19 J.
b) If the impact test pieces from plate materials are taken with their longitudinal axes parallel with the maindirection of rolling, the average value from 3 tests for the fusion line and the heat affected zone shall notto be less than 41 J, and for the weld metal not less than 27 J. One single test may give a value belowthe required average but not lower than 29 J and 19 J respectively. For testing of thin materials where itis impossible to use a standard test piece 10 × 10 mm, the larger of the following pieces shall be used:10 × 7.5 mm or 10 × 5 mm.
The impact value requirements are then reduced to respectively 5/6 and 2/3 of the required values for thestandard test pieces.For retesting, see Ch.1 Sec.2 [3.8].
10.1.1 Impact testing shall be as described in [3.2.8] using an impact test temperature of –20°C, or –5°Cbelow the design temperature whichever is lower. The average value for absorbed energy shall not be lessthan 27 J. Other test requirement can be agreed for individual cases.
10.1.2 When a butt weld is made between dissimilar material grades, both sides of the weld (HAZ) shall beimpact tested.
10.1.3 The hardness of the HAZ after welding shall, unless otherwise agreed, not exceed the maximumhardness specified for the base material, and the hardness of the weld metal shall not exceed the maximumhardness specified for the weld deposit of the applied welding consumable.Unless other requirements are specified for the applicable base materials and welding consumables, thefollowing requirements applies:
— for 22 Cr Duplex: Max. 290 HV10 or 28 HRC— for 25 Cr Duplex: Max. 330 HV10 or 32 HRC.
10.1.4 Type 25Cr duplex shall be corrosion tested according to ASTM G48 Method A. The test specimen shallbe in the as welded state after normal weld cleaning operation. The test specimens shall be exposed to the
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 72Fabrication and testing
DNV GL AS
solution at a constant temperature of 40°C for 24 hours. The test specimens shall have a dimension of fullwall thickness by 25 mm along the weld and 50 mm across the weld. The test shall expose the external andinternal surface and a cross section surface including the weld zone in full wall thickness. Cut edges shallbe prepared according to ASTM G48. The whole specimen shall be pickled before being weighed and tested.Pickling may be performed for 5 min. at 60ºC in a solution of 20% HNO3 + 5% HF.The following test requirements shall be fulfilled:
— there shall be no pitting at 20X magnification— general weight loss shall be less than 4.0 g/m2.
Guidance note:Welds between ferritic-austenitic steels and other grades of stainless, C/Mn steels or for welds in “non-corrosive” area may notneed to be corrosion tested.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
10.1.5 Duplex stainless steel types shall be microstructurally examined and the test samples shall comprisethe weld metal, heat affected zone and base metal. The microstructure shall be suitably etched andexamined at 400X to 500X magnification and shall be free from grain boundary carbides and precipitates.The ferrite content in the weld metal root and un-reheated weld cap shall be determined in accordance withASTM E562 and be in the range of 30-70%.
10.2 Validity of a qualified welding procedure
10.2.1 Reference is made to [6] and any change in the following additional essential variables which shalllead to a new qualification:
— variation in the heat input greater than ±15%.
11 Additional requirements for welding procedure qualification testof austenitic steel
11.1 Welds in plates and pipes
11.1.1 When welding procedure qualification tests are required, the tests shall be performed in accordancewith [3.2.1] or [3.3.1] and the supplementary requirements given below. The welding procedure qualificationtests shall cover all relevant dimensions, positions and material combinations. Details regarding essentialvariables and validity of the procedure shall be as given in [6]. Mechanical testing acceptance requirementsshall be as given in [5], if not otherwise specified below.
11.1.2 Impact testing is not required for design temperatures above –105°C. For low temperatureapplication reference is made to [9].
11.1.3 Hardness testing is not required.
11.1.4 Depending on the field of application or if required for the base material, additional corrosionprotection tests shall be performed within the scope of welding procedure tests, e.g. testing of resistanceagainst intergranular corrosion.
11.2 Test requirements
11.2.1 If impact testing is required, the testing shall be conducted at –196°C meeting an average impactenergy level of minimum 27 J.
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 73Fabrication and testing
DNV GL AS
11.3 Range of approval
11.3.1 The requirements of [6.2] apply. In addition a change to a grade of higher specified strength orhigher impact toughness requirements shall lead to a new qualification.
12 Welding procedures qualification for aluminium
12.1 General
12.1.1 Basic requirements are given in [1] General and [2] Welding procedure specification.
12.1.2 Welding consumables shall be one of those recommended in Sec.4 Table 7.
12.2 Butt welds in plates
12.2.1 Test assembly shall be as described in [3.2.1].
12.2.2 The following mechanical tests are required from each assembly:
— 2 cross-weld tensile test specimen— 2 root and 2 face or 4 side bend specimens— 1 macro test specimen.
For the location of test specimens, see Figure 24.
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 74Fabrication and testing
DNV GL AS
Figure 24 Location of test specimens for a butt weld on plate
12.2.3 Two cross-weld tensile specimens shall be taken from each of the welded assemblies. The testspecimen dimensions are given in Ch.1 Sec.3 [3.1.9].Side bend tests shall be carried out for thickness equal to and above 12 mm. Four bend specimens shall betaken from each of the welded assemblies. The bend test specimens shall be machined to the dimensionsgiven in Ch.1 Sec.3 [3.4].
12.2.4 For thickness below 12 mm two face bend and two root bend test specimens shall be taken. Thediameter of the bending mandrel shall be as given in [12.6.2].
12.2.5 One macrosection shall be prepared from the test assembly to reveal the weldment macro structure.The macrosection shall be visually inspected using a magnification of 5X to 10X.
12.3 Butt welds in pipes
12.3.1 Test assembly shall be as described in [3.3.1].
12.3.2 The following mechanical tests are required from each assembly:
— 2 cross-weld tensile test specimen— 2 root and 2 face or 4 side bend specimens— 1 macro test specimen.
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 75Fabrication and testing
DNV GL AS
Figure 25 Location of test specimens for a butt weld in pipe
12.3.3 Two cross-weld tensile specimens shall be taken from each of the welded assemblies. The testspecimen dimensions are given in Ch.1 Sec.3 [3.1.9].
12.3.4 Side bend tests shall be carried out for thickness equal to and above 12 mm. Four bend specimensshall be taken from each of the welded assemblies. The bend test specimens shall be machined to thedimensions given in Ch.1 Sec.3 [3.4].
12.3.5 For thickness below 12 mm two face bend and two root bend test specimens shall be taken. Thediameter of the bending mandrel shall be as given in [12.6.2].
12.3.6 One macrosection shall be prepared from the test assembly to reveal the weldment macro structure.The macrosection shall be visually inspected using a magnification of 5X to 10X.
12.4 Branch connectionsThe following mechanical tests are required from each assembly, see Figure 11:
— two macrosection tests at 12 and 6 o'clock.
12.5 Fillet welds
12.5.1 Test assembly shall be as described in Figure 12.The following tests shall be performed:
— two macrosection tests. One of the macrosections shall be taken at the marked position of the stop/restart. The macrosection shall include about 10 mm of unaffected base material and shall be preparedand etched on one side to clearly reveal the fusion line and the HAZ
— one fracture test shall be performed by folding the upright plate onto the through plate. Evaluation shallconcentrate on cracks, porosity and pores, inclusions, lack of fusion and incomplete penetration.
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 76Fabrication and testing
DNV GL AS
Non-destructive testing of test assemblies:Non-destructive testing shall be according to [4.1] for butt joints, T-, K-, and Y-joints and [4.2] for filletwelds and partial penetration welds.
12.6 Mechanical testing
12.6.1 The tensile strength of the test specimens shall not be less than specified for the parent alloy in Table14.
Table 14 Mechanical properties in the welded condition
12.6.2 The bend test specimens shall be bent on a mandrel with maximum diameter as given in the formulabelow. The bending angle shall be minimum 180°. After bending, the test specimens shall not reveal anyopen defects greater than 3 mm in any direction. Smaller cracks developing from the edges of the specimensshall not normally be considered as significant, unless there is definite evidence that they result frominclusions or other defects. «Wrap around» bending as shown in Ch.1 is the preferred bending method.
Where:
D = maximum former diameterts = thickness of the bend test specimen (this includes side bends)A = minimum tensile elongation required by the material specification (for combination between
different alloys, the lowest individual value shall be used).
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 77Fabrication and testing
DNV GL AS
12.6.3 The macrosections shall show a regular weld profile with smooth transitions to the base materialsand without significant or excessive reinforcement. Cracks and lack of fusion are not acceptable. The filletweld fracture test as well as the macro examination shall satisfy the acceptance level in EN ISO 10042 qualitylevel B except for excess weld metal or convexity, excess throat thickness and excess of penetration forwhich the level C applies.
12.6.4 When a butt weld is made between two plates of different alloys the tensile strength to be obtainedon the welded assembly shall satisfy the requirements of the alloy with the lower strength.
12.6.5 If the WPQT fails to comply with any of the requirements for NDT, one extra WPQT shall be weldedand subjected to the same testing. If this additional test does not meet the relevant requirements, the actualWPS shall be considered as not qualified and a re-specification of the WPS shall be made prior to a newWPQT.
12.7 Range of qualification
12.7.1 The validity of approved WPS shall be as given in [6.1].
12.7.2 A qualified WPS shall be used within the ranges of the welding parameters as given below.Base materialThe following changes shall lead to a new qualification:
a) in general, significant change of material properties which will obviously affect the weldability andmechanical properties
b) more specifically, aluminium alloys are grouped in the following categories:
For each group, the qualification made on one alloy qualifies the procedure also for the other alloys within thesame group with equal or lower specified tensile strength after welding.The qualification made on group 2) alloy, qualifies the procedure also for group 1) alloys.A dissimilar metal joint shall be qualified by the same dissimilar combination.ThicknessThickness, t, is defined as follows:
a) for a butt weld: The base metal thickness, which for welds between dissimilar thicknesses is that of thethinner material
b) for a fillet weld: The base metal thickness, which for welds between dissimilar thicknesses is that of thethicker material. However, for each thickness range qualified, as given in Table 15 and Table 16 there isan associated range of qualified throat thickness
c) for a set-on branch connection: The thickness of the branch piped) for a set-in or set-through branch connection: The thickness of the main pipee) for a T-joint in plate: The thickness of the prepared plate.
The requirements for qualified thickness range for butt welds shall be as given in Table 15.
Table 15 Qualified thickness range
Thickness of test piece, t [mm] Qualification range [mm]
t ≤ 3 0.5 × t to 2 × t
3 < t ≤ 20 3 to 2 × t
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 78Fabrication and testing
DNV GL AS
Thickness of test piece, t [mm] Qualification range [mm]
t > 20 ≥ 0.8 × t
In addition to the requirements of Table 15, the range of qualification of the throat thickness “a” of filletwelds is given in Table 16.
Table 16 Range of qualification for the throat thickness for plates and pipes
Throat thickness of the test piece, a [mm] Range of qualification [mm]
a < 10 0.75 × a to 1.5 × a
a ≥ 10 ≥ 7.5
Where a fillet weld is qualified by means of a butt weld test, the throat thickness range qualified shall bebased on the thickness of the deposited weld metal.Diameter of pipes and branch connectionsThe qualification of a welding procedure test on diameter D qualifies diameters in the ranges given in Table17.
Table 17 Qualified range for pipe and branch connection diameters
Diameter of the test piece, D [mm] 1) Qualification range [mm]
D ≤ 25 0.5 × D to 2 × D
D > 25 ≥ 0.5 × D and plates
1) D is the outside diameter of the pipe or outside diameter of the branch pipe
Angle of branch connectionsA WPQT carried out on a branch connection with angle α shall qualify all branch connection angles in therange of α to 90°.
Welding consumablesThe following changes shall lead to a new qualification:
— any change in consumable classification— any significant change of shielding gas mixture.
Welding positionsThe following changes shall lead to a new qualification:
— change from one principal welding position to another, see Figures in [6.2], unless complying with Table18.
Type of jointThe following changes shall lead to a new qualification:
— change from fillet weld to butt weld— change from two sided welding to one side, but not vice versa— deletion of back gouging— deletion of backing— change from butt joint in plates to butt joints in pipes with outside diameter less than 500 mm— any change of groove dimensions specified in the WPS.
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 79Fabrication and testing
DNV GL AS
Welding conditionThe following changes shall lead to a new qualification:
— any change of welding process— change from spray arc to short arc or pulsed arc or vice versa— change in heat input beyond ±25%— any increase in preheat temperature for heat-treatable alloys when the specified preheat is above 50°C— any decrease in preheat temperature— higher interpass temperature than that used in the WPQT— change of heat treatment used in the WPQT. Holding time may be adjusted as a function of thickness— change from weaving to stringer bead technique or vice versa— change from multi-pass welding to one-pass welding— change in type of cleaning method (chemical or mechanical)— change in welding current from A.C. to D.C. or vice versa, or change in polarity.
Table 18 Qualified principal positions for butt welds and fillet welds, aluminium
Qualified positions 3)
Butt weldsTest weld
joint configuration 1, 2)Principal
positionsPlates Pipes
Fillet welds
plates or pipes
Butt welds in plates
1G
2G
3G
4G
1G
1G, 2G, 3G
1G, 2G, 3G
All
1G
1F
1F, 2F, 3F
1F, 2F, 3F
All
Butt welds in pipes
1G
2G
5G
1G
1G, 2G, 3G
All
1G
2G
1G, 5G
1F
1F, 2F, 4F
All
Fillet welds
1F
2F
3F
4F
5F
1F
1F, 2F, 3F
1F, 2F, 3F
All
All
1) pipes with D > 500 mm are considered equivalent to plates (apply only to the main pipe in branch connections)2) branch connections shall be qualified separately3) the vertical downwards position shall be qualified separately.
12.8 Retesting
12.8.1 If the WPQT fails to comply with any of the requirements for NDT, one extra WPQT shall be weldedand subjected to the same testing. If this additional test does not meet the relevant requirements, the actualWPS shall be considered as not qualified and a re-specification of the WPS shall be made prior to a newWPQT.If the result of any destructive test fails to meet the requirements, two further tests may be made from thesame welded joint if there is sufficient material available. If not, a new assembly shall be welded using thesame pWPS. If either of these additional tests do not comply with the relevant requirements, the pWPS shallbe regarded as not capable of complying with the requirements without modification.
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 80Fabrication and testing
DNV GL AS
13 Welding procedure qualification, copper alloys
13.1 Pipes, plates, castings and other product forms, not including propellercastings
13.1.1 WPS for pipes and plates shall be qualified in accordance with ISO 15614-6 unless otherwise agreed.
13.2 Copper alloy castings for propellers
13.2.1 General recommendations for filler metal and pre- and post-weld heat treatment of copper alloypropeller castings are given in Table 19.
Table 19 Recommendations for welding of copper alloy propeller castings
Alloy type Description
Mn-bronze, Cu1 Use Al-bronze 1) or Mn-bronze filler metal. Preheat to 150oC and interpasstemperature not to exceed 300oC. Stress relief at 350oC to 500oC.
Mn-Ni-bronze, Cu2 Use Al-bronze or Mn-Ni-bronze filler metal. Preheat to 150oC and interpasstemperature not to exceed 300oC. Stress relief at 350oC to 550oC.
Ni-Al-bronze, Cu3 Use Al-bronze, Ni-Al-bronze 2) or Mn-Al-bronze filler metal. Preheat to 100oC andinterpass temperature not to exceed 250oC. Stress relief at 450oC to 500oC.
Mn-Al-Bronze, Cu4 Use Mn-Al-bronze filler metal. Preheat to 100oC and interpass temperature not toexceed 300oC. Stress relief at 450oC to 600oC.
1) Ni-Al-Bronze and Mn-Al-Bronze acceptable2) if Ni-Al-Bronze is used, stress relief is not required.
13.2.2 For qualification of WPS, a test assembly of minimum 30 mm thickness shall be welded. See Figure26.
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 81Fabrication and testing
DNV GL AS
Figure 26 Weld test assembly
13.2.3 Prior to sectioning, the test assembly shall be visually inspected and liquid penetrant tested inaccordance with a recognized standard, e.g. ISO 3452, ASTM E165. Imperfections shall be assessed inaccordance with Table 20.
Table 20 Allowable number and size of indications depending on severity zones
Severity zone Maximum totalnumber of indications Indication type Maximum number
for each type 1, 2)
Maximumdimension ofindications[mm]
Non-linear 5 4A 7
Linear or aligned 2 3
Non-linear 10 6B 14
Linear or aligned 4 6
Non-linear 14 8C 20
Linear or aligned 6 6
1) single non-linear indications less than 2 mm in zone A and less than 3 mm in other zones may be disregarded2) the total number of non-linear indications may be increased to the maximum total number, or part thereof,
represented by the absence of linear or aligned indications.
13.2.4 Three macro-sections shall be prepared and etched on one side to clearly reveal the weld metal,the fusion line, and the heat affected zone. The sections shall be visually inspected for any imperfections
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 82Fabrication and testing
DNV GL AS
present in the weld metal and HAZ. Inclusions or pores greater than 3 mm and cracks or lack of fusion arenot permitted.
Guidance note:An etching medium with the following constituents is suitable for this purpose:
— 5 g ferric (III) chloride
— 30 ml hydrochloric acid
— 100 mm distilled water.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
13.2.5 Two tensile test pieces shall be prepared as shown in Figure 27. The tensile strength for copper alloypropeller castings shall meet the specified minimum values given in Table 21. The tensile strength for othercopper alloy castings shall meet the requirements for the base material. The location of fracture shall bereported, i.e. weld metal, HAZ or base material.
13.2.6 For welding procedures qualified according to this chapter, all thicknesses are qualified. Range ofapproval for other parameters shall follow ISO 15614-6 unless otherwise agreed.
Figure 27 Tensile test specimen for weld test assembly
Table 21 Tensile strength requirements for WPQT
Alloy type Tensile strength [N/mm2]
Mn-Bronze, Cu1 (brass) 370
Mn-Ni-Bronze, Cu2 (brass) 410
Ni-Al-Bronze, Cu3 (bronze) 500
Mn-Al-Bronze, Cu4 (bronze) 550
14 Welding procedure qualification, repair welding of steel castings
14.1 General
14.1.1 These requirements are applicable to repair welding of steel castings, including stainless steelpropeller castings.
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 83Fabrication and testing
DNV GL AS
14.2 Welding procedure qualification test
14.2.1 For qualification of procedures, a test assembly of minimum 30 mm thickness shall be welded.
14.2.2 Prior to sectioning, the test assembly shall be visually inspected and liquid penetrant tested.Imperfections shall be assessed in accordance with Ch.2 Sec.8 [4.6].
14.2.3 Two macro-sections shall be prepared and etched on one side to clearly reveal the weld metal, thefusion line, and the heat affected zone. The sections shall be examined by eye for any imperfections presentin the weld metal and HAZ. Cracks or lack of fusion are not permitted.Inclusions or pores greater than 3 mm are not permitted.
14.2.4 Two flat transverse tensile test pieces shall be prepared. The tensile strength shall meet the specifiedminimum value of the base material. The location of fracture shall be reported, i.e. weld metal, HAZ or basematerial.
14.2.5 Two transverse side bend test pieces shall be prepared. The former diameter shall be 4 times thethickness except for austenitic steels, in which case the mandrel diameter shall be 3 times the thickness. Thetest piece, when visually inspected after bending, shall have no surface imperfections greater than 2 mm inlength.
14.2.6 Where impact test is required for the base material, Charpy V-notch impact toughness test isrequired in accordance with [3.2.8]. For stainless steel propeller castings, two sets would suffice; one setwith the notch positioned in the centre of the weld and one set with the notch positioned in the fusion line.The test temperature and absorbed energies shall comply with the requirements for the base material.
14.2.7 One of the macro-sections shall be used for hardness testing. Indentations shall traverse 2 mm belowthe surface. Minimum three individual indentations shall be made in the weld metal, the HAZ (both sides)and in the base material (both sides). The values shall be reported for information.
14.2.8 The chemical composition of the deposited metal shall be analysed and the result shall be within thesame category as the parent metal.
14.3 Range of validity
14.3.1 The qualification is valid for repair welding on all thicknesses and bevel configurations.For limitations to range of approval for material grades, heat input and welding consumables, see [6].
Part 2 Chapter 4 Section 5
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 84Fabrication and testing
DNV GL AS
SECTION 6 FABRICATION AND TOLERANCES
1 General
1.1 Scope
1.1.1 This section specifies general requirements for steel structure fabrication processes, including essentialvariables, which shall be maintained and controlled by the builders. The designing and dimensioning ofwelded joints in the various ranges of application is additionally governed by specific requirements stated inPt.3 and Pt.4.
1.2 Required compliance documentation
1.2.1 Required compliance documentation is given in Sec.1 [3.1].
1.3 Documentation requirements
1.3.1 Documentation requirements are given in Sec.1 [3.2].
1.4 Survey, inspection and testing requirements
1.4.1 General survey, inspection and testing requirements are given in Sec.1 [3.3]. Additional specificrequirements are given in Table 1, as further detailed in this section.
Table 1 Additional survey and testing requirements
Survey, inspection and testing item Description
Fit-up inspections
Fit-up shall be checked for dimensional accuracy beforewelding by the builder, in order to ensure compliance with theweld shapes and root openings (air gaps) according to themanufacturing documents and approved WPS. The surveyor mayrequest to attend on a case by case basis.
Weldability In case of doubts, the weldability of the materials shall be verifiedbefore welding commences to the satisfaction of the surveyor.
Welding production tests (WPT) As verification of the quality of produced welds WPT may berequired by the surveyor.
Welding consumablesThe welding shop’s supervisors shall ensure that only weldingconsumables which have been approved by the Society are beingused and shall furnish proof thereof to the surveyor on request.
Part 2 Chapter 4 Section 6
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 85Fabrication and testing
DNV GL AS
2 Material, identification and weldability
2.1 General
2.1.1 A material identification system which ensures correct installation and traceability documentation ofthe material grades shall be established.
2.1.2 Welded structures shall be fabricated using base materials of proven weldability, see Ch.2 Sec.2.Special attention shall be paid regarding the approval of hull structural steels intended for welding with heatinput more than 50 kJ/cm. In case of doubt, the weldability of the materials shall be verified before weldingcommences.
3 Shop primers
3.1 General
3.1.1 Shop primer including temporary corrosion/oxidation preventive coatings applied over areas, which willsubsequently be welded without removal of the primer/coating, shall be type approved in accordance withDNVGL-CP-0109.
3.1.2 Fully mechanized fillet welding over shop primer shall be approved for each type of shop primer by awelding procedure qualification test (WPQT), see Sec.5.
Guidance note:Type approved shop primers are listed in the Society register of approved products and manufacturers, available on the DNV GLinternet site.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
4 Welding environment
4.1 General
4.1.1 Welding work shall not be carried out in environmental conditions that have a detrimental effect suchas wind, damp and low temperatures.
Guidance note:If preheating at temperature above ambient is not already required or recommended, see [5.3.8], recommendations for preheatingfor welding at low temperatures are given in IACS Rec. No. 47, Table 6.12.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
4.1.2 The grooves shall be clean and dry at all time of welding.
4.1.3 Preheating temperature, whenever required, shall in any case be within the limit of essential variables,see [5.3.8].
4.1.4 The welding interpass temperature shall not drop below the minimum required preheating temperatureand shall not exceed the maximum qualified interpass temperature.
4.1.5 During the entire construction period, suitable measures shall be taken in transport, storage andfabrication to keep the surface of stainless steels free from impurities and extraneous metallic inclusions.
Part 2 Chapter 4 Section 6
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 86Fabrication and testing
5.1.1 Cut edges shall be accurate and uniform in order to provide a shape compatible with the weld jointdesign.
5.1.2 Deviation of cut edges shall generally be within the standard specified by IACS Rec. No.47 Shipbuildingand Repair Quality Standard Part A.
5.1.3 Attention shall be paid to avoid excessive local hardening and carbon contaminations by thermalcutting.
Guidance note:For extra high strength materials with SMYS above 500 MPa and with thickness more than 50 mm it is recommended to dopreheating before flame cutting, with a preheating temperature according to the recommendations given by the manufacturer(steel mill). Further, it is recommended to examine the flame cut surface 100% by MT.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
5.1.4 The effect of work hardening and risk of cracked edges shall be considered if shearing is used forcutting of material.
5.1.5 Correction by welding as compensation for improper cutting shall be in accordance with procedures forrepairs.
5.2 Forming
5.2.1 Forming and straightening of materials shall be performed according to procedures which outline thesuccession of the controlled steps.
5.2.2 Requirements for cold forming of hull structural steels, e.g. minimum steel grade toughnessrequirements (D/DH), and maximum theoretical deformation (5%, 10% and 20%, as specified), are given inPt.3 Ch.3 Sec.1 [2.7].Cold forming of extra high strength steel is limited to 5% for material strength grades up to VL 690 unlessotherwise agreed and qualified.Maximum cold forming ratio of material strength grades VL 890 and VL 960 shall be agreed.
Guidance note:Qualification by adequate testing is advised, e.g. tensile test and impact tests of representatively strained and strain aged material.Weldability test may be considered.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
5.2.3 Cold forming with theoretical deformation exceeding the limits given in Pt.3 Ch.3 Sec.1 [2.7] maybe accepted for material strength grades up to VL 690 subject to additional testing of representatively coldformed material , e.g. strain age testing. The strain age test method is described in Ch.1 Sec.3 [3.9], andacceptance criteria for the tests are given in Pt.3 Ch.3 Sec.1 [2.7]. Unless otherwise agreed, each castrepresented shall be tested.Cold forming to an inside bending radius of less than 2 times the plate thickness shall in no case be carriedout, unless specially approved.
Part 2 Chapter 4 Section 6
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 87Fabrication and testing
DNV GL AS
Guidance note:In addition to representative cold forming, in this context "representative material" means at least same material grade, withsimilar chemical composition and mechanical properties, and from one steel manufacturer. For destructive testing, the followingshould be tested as a minimum; impact toughness tests of representatively strained material and strain aged material. Testtemperature should be the same as required for the base material.Where certified elongation for the material to be cold formed, minus calculated theoretical deformation gives a value lower than9%, tensile test of strained material is advised. Measured residual elongation should be more than 10%.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
5.2.4 Cold forming to a theoretical deformation exceeding the limits given in [5.2.3] may be pre-qualified bythe manufacturer. The pre-qualification is subject to special consideration and with agreed additional processand testing requirements.
5.2.5 If welding is applied in areas cold formed to more than the limits given in [5.2.2], special considerationshall be taken with respect to material properties and subsequent cracking, e.g. by additional inspection andNDT.
5.2.6 The theoretical plastic deformation є (%) shall be calculated by the following simplified formulas:
Single-curvature deformation
Cold rolling or pressing of plates to cylindrical forms:
(1)
Cold bending of straight pipes to bends:
(2)
Double curvature deformation
Forming of plates to spheres:
(3)
where:
D = outside diameter of pipe of vessel, mmє = theoretical plastic deformation, %Rc = forming radius (inner radius of bend), mmt = material thickness, mmv = Poisson’s ratio (0.5 for plastic condition).
5.2.7 Forming of steels at high temperatures shall be effectuated with due regard to adverse effects ofthe material’s properties. Forming of steels above 650°C shall be subject to agreement with the Society,considering steel manufacturer’s recommendation.
5.2.8 Welds shall not be cold formed.
Part 2 Chapter 4 Section 6
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 88Fabrication and testing
DNV GL AS
Guidance note:Approval may be given on a case by case basis where pre-qualification tests may be required depending on the deformation rate,the material and welding consumable properties.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
5.3 Assembly and welding
5.3.1 Members to be welded shall be brought into correct alignment and held in position by clamps, tackwelds, or other suitable devices. Structures or components shall not be subjected to any appreciablemovements or vibration during welding.
5.3.2 Parts to be assembled while suspended from cranes or floating shall be clamped prior to tack-weldingof the joints, in such a way that no relative movement of the parts is possible. Components which have notbeen fully welded and which shall be handled or turned shall have welded joints of adequate strength.
5.3.3 Fit-up shall be checked for dimensional accuracy before welding, in order to ensure compliance withthe weld shapes and root openings (air gaps) according to the manufacturing documents and approved WPS.The root opening shall not exceed twice the specified gap as given in the approved WPS. The standard rangeand limit range as defined in IACS Rec.No.47 shall be met in regular work under normal circumstances.Special attention shall be paid to the alignment of structural members where visual inspection is not possible.
5.3.4 If the permitted size of the gap is exceeded locally over a limited area, remedial work shall be carriedout within the limitations specified in IACS Rec. No.47.
5.3.5 Surfaces to be welded shall be free from mill scale, slag, rust, paint or other contaminating substances.For overweldable shop primers, see [3].
Guidance note:Internal defects, e.g. inclusions making the steel plate prone to lamination, may to some extent be considered consistent withmethod of manufacture, unless Z-grade steels are specified. Purchasers should specify additional requirements for the internalquality (e.g. ultrasonic testing) where this is critical for the intended application.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
5.3.6 Grooves produced by gouging shall be followed by grinding removing carbonized material.
5.3.7 All welding, including tack welding, seal welding, welding of lifting lugs and attachment welds as wellas repair welding, shall be performed within the limits of essential variables of the qualified WPS.
5.3.8 The need and the degree of preheating necessary for welding are governed by a series of factors(see guidance note). If preheating is necessary for welding it shall be applied in accordance with agreedpreheating procedures. Special attention shall be paid to temperature control during the welding processsuch that the preheat temperature is kept uniformly in affected part of the welded object.
Part 2 Chapter 4 Section 6
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 89Fabrication and testing
DNV GL AS
Guidance note:Normal strength steels may require preheating depending on the plate thicknesses and the degree of joint restraint.Preheating is normally required for welding of high and extra high strength steels depending on:
— plate thickness
— the chemical composition of the parent material and weld metal
— the hydrogen content of the weld metal
— heat input during welding
— the temperature of the welded object
— the stress level (incl. the joint restraint condition)
— post heating may additionally be required for extra high strength steels.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
5.3.9 The welding sequence shall be such that the amount of shrinkage, distortions and residual stresses areminimised.
Guidance note:Welding should be performed in the optimum welding position. Positional welding (e.g. in the overhead positions) should be limitedto the indispensable minimum.Vertical down fillet welding should not be used:
— for joining together continuous primary supporting members interrupted by transverse members (e.g. the longitudinalmembers of the upper and lower girder); the same applies where transverse loads predominate
— for mainly dynamically loaded welded joints (e.g. in the area of engine base plates, shaft, brackets and rudders)
— on crane components and other lifting gear including their substructures (e.g. crane pillars)
— at intersections of main girders and in the area of the supports or stoppers of hatchway covers.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
5.3.10 Welds shall be terminated in a manner such that all welds are sound and without end craters. Run-in and run-off plates shall be used, where practicable. They shall be removed upon completion and cooling ofthe weld. Cut welds shall be made smooth and flush with the edges of the abutting parts.
5.3.11 Tack welding shall, when integrated in production weld, be carried out in accordance with approvedWPS specifying the applied minimum welding length.
5.3.12 Tack welds, if retained as part of the welding process, shall be free from defects and provideadequate conditions for pass welding. Cracked tack welds shall not be welded over.
5.3.13 Clamping plates, temporary ties and aligning pins shall be made from a material of similarcomposition and should not be used more than necessary. Any damage caused during removal shall becompetently repaired.
5.3.14 For welding of stainless steels and where reduced corrosion resistance would be detrimental forthe intended use, the root and cap side shall be sufficiently protected by shielding gas in order to avoiddetrimental oxidation (tinting). Alternatively, the detrimental oxides may be removed by pickling andpassivation.
Guidance note:Oxygen content of the backing gas may typically be not more than 50 ppm in order to avoid excessive oxidation. Color maps forevaluation of high temperature discoloration/tinting on stainless steels are found in some standards, e.g. AWS D18.2 and NORSOK-M601.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
5.3.15 The welding consumables (including flux, backing, welding gas, etc.) shall enable a welded joint to bemade which is suited to the base material and the operating conditions.
Part 2 Chapter 4 Section 6
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 90Fabrication and testing
DNV GL AS
5.3.16 Storage and handling of welding consumables shall be in accordance with the manufacturer’srecommendations, and in accordance with procedures giving details regarding conditions in storage rooms,temperature in storage ovens and quivers, length of exposure and conditions.
5.3.17 Consumables which have been contaminated by moisture, rust, oil, grease, dirt or other deleteriousmatters, shall be discarded unless properly reconditioned.
5.3.18 Recycling of fluxes for SAW shall be performed in a manner that ensures a mixture of new and usedflux with continually homogenous properties.
5.3.19 The welding shop’s supervisors shall ensure that only welding consumables which have beenapproved by the Society are used. Proof thereof shall be furnished to the surveyor on request. Weldingconsumables specified in an approved welding procedure can only be replaced by equivalent consumablesapproved by the Society with an appropriate quality grade. Further details are given in Sec.5.
5.3.20 Additional requirements applicable for VL D/E47COD, BCA and BCACOD steels:
— Wherever possible, multi-pass welding shall be applied.— Tack welds shall have a length not less than 50 mm. For steel with Pcm ≤ 0.19, tack welds with length notless than 25 mm may be accepted subject to qualification and approval.
— Preheating shall be 50°C or over when air temperature is 5°C or below. For steel with Pcm less than orequal to 0.19 and subject to qualification and approval, air temperature below 5°C may be accepted. Thepreheating temperature shall be measured at a distance of 75 mm from the edges of the groove at theopposite side of the heating source, or as close as possible to this position. When preheating is required,the temperature shall be strictly controlled.
Guidance note:For the required preheating, electric heating elements are considered adequate in order to give sufficient temperature control.When preheating is not strictly required by the rules, and air temperature below 5°C is accepted without preheating, dryingout using a properly designed gas torch should be considered. Cutting torch is considered not suitable for drying out. For repairwelding, preheating temperature should be increased 50°C above minimum specified preheating temperature given by theWPS.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
— Special care shall be paid to the final welding so that harmful defects do not remain. Jig mountings shallbe completely removed and absence of defects in former JIG welds areas shall be verified by MT. If thereare defects present after JIG removal, means for correction shall be accepted by the Society.
— Welding procedures (WPS) shall be qualified through welding procedure qualification test (WPQT) asdescribed in Sec.5 [7] for BCA steels and Sec.5 [8] for COD and BCACOD steels.
— Verification of the WPS during welding shall be carried out and recorded.— Gouging shall be followed by grinding to remove any carburised layer. The surveyor may require proof ofsatisfactory performance of gouging and grinding.
— Arc strikes shall be repaired by mechanical removal of affected base material followed by magneticparticle testing (MT) in order to verify absence of cracks.
5.3.21 When deemed necessary by the Society, WPT shall be made during fabrication of welds to verify thatthe produced welds are of acceptable quality.
6 Remedial
6.1 General
6.1.1 Guidance to general welding repair work is given in IACS Rec. No.47 Shipbuilding and Repair QualityStandard Part A.
Part 2 Chapter 4 Section 6
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 91Fabrication and testing
DNV GL AS
6.1.2 Defects in welds may be repaired by grinding or machining and/or followed by welding. In order toverify complete removal of defects, affected areas shall be examined with suitable NDT methods.
6.2 Repair welding
6.2.1 Repairs by welding shall be carried out in accordance with approved WPS. Mechanical properties shallsatisfy the minimum specified properties of the material in question.
6.2.2 Repair welding in the same area shall not be carried out more than twice. Further repairs shall besubject to agreement with the Society.
6.2.3 Defects shall be completely removed before necessary repairs are carried out. Repairs with arc-airgouging shall be followed by grinding.
6.2.4 Repair welding of post-weld heat-treated joints shall unless otherwise agreed initiate a new heattreatment.
6.2.5 All weld repairs shall at least be re-inspected with the same NDT methods as originally applied, seealso Sec.7 [6.2].
6.3 Flame straightening
6.3.1 Members distorted by welding may be straightened by mechanical means or by a limited amount oflocalized heat.Flame straightening shall be done in accordance with an agreed procedure.
6.3.2 Corrective measures relating to flame straightening shall be carried out with due regard to possibledegradation of the material properties on the surface for normal and high strength hull structural steels.See IACS Rec. No.47 Shipbuilding and Repair Quality Standard Part A Table 6.5, regarding max. temperatureon the surface.
7 Inspection, survey and tolerances
7.1 General
7.1.1 Inspection shall be carried out in accordance with inspection and test plans, to confirm that work iscarried out in accordance with established project procedures and plans, such that all project requirementsare complied with to the satisfaction of the Society. Reference is given to IACS UR Z23 regarding the surveyof hull structure.
7.1.2 Due consideration shall be given to the access and time required for adequate inspection and surveyduring fabrication.
7.1.3 High non-conformance rates in execution of the work or in the product itself shall call for specialconsiderations in agreement with the Society. Such special considerations may include increased inspectionby the builder, increased surveys by the Society, re-qualification of personnel and other agreed remedialactions.
Part 2 Chapter 4 Section 6
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 92Fabrication and testing
DNV GL AS
7.2 Alignment and straightness
7.2.1 Allowable acceptable alignment shall be established depending on the criticality of the design. Specialrequirements related to special type and service are given in Pt.5.
7.2.2 Unless otherwise agreed, fabrication tolerances shall be in compliance with IACS Rec. No.47Shipbuilding and Repair Quality Standard, Part A.
7.3 Weld production test requirements
7.3.1 The Society may require WPTs to be carried out. The extent and type of testing shall be agreed withthe Society.
7.3.2 When WPTs are required the test assembly and test requirements shall comply with relevantrequirements of Sec.5.
7.3.3 If the achieved test results do not comply with the requirements of Sec.5, the results shall besubmitted for consideration. The WPT may be accepted subject to acceptable results from additional testprescribed by the Society.
Part 2 Chapter 4 Section 6
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 93Fabrication and testing
DNV GL AS
SECTION 7 NON DESTRUCTIVE TESTING OF WELDS
1 General
1.1 Scope
1.1.1 This section provides requirements for the builder or its sub-supplier quality control of ship hull weldsin the newbuilding phase.The section contains requirements for:
— the application of non-destructive testing (NDT) activities— the application and the competence and control needed to perform non-destructive testing (NDT) serviceand activities
— NDT methods, extent of testing, acceptance criteria and procedures— the NDT suppliers, further detailed in Sec.2.
Guidance note:For NDT activities it is recommended that the builder or its sub-supplier may be approved according to DNVGL-CP-0484 App.B [4]or comply with other recognized standards e.g. ISO/IEC 17020 Type A or B or ISO/IEC 17025.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
1.1.2 Additional requirements for extent of testing and acceptance criteria are given in Pt.5 for the relevantship types.
1.2 Required compliance documentation
1.2.1 Required compliance documentation is given in Sec.1 [3.1].
1.3 Documentation requirements
1.3.1 Documentation requirements are given in Sec.1 [3.2]. Additional documentation requirements aregiven in DNVGL-CG-0051.
1.4 Survey, inspection and testing requirements
1.4.1 General survey, inspection and testing requirements are given in Sec.1 [3.3]. Additional specificrequirements are given in Table 1.
Table 1 Additional survey and testing requirements
Survey, inspection and testing item Description
NDT inspections NDT reports shall be signed by the NDT operator performing the testing.
Part 2 Chapter 4 Section 7
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 94Fabrication and testing
The testing operators and supervisors shall be certified according to a thirdparty certification scheme based on ISO 9712:2012 (or later version) or ASNTcentral certification programme (ACCP). SNT-TC-1A according to ANSI/ASNTCP-189:2016 (or later versions) may be accepted if the NDT company`s writtenpractice is reviewed and accepted by the verfier. The surveyor shall be furnishedwith proof thereof if he/she so requests.
The supervisor(s) / level 3 shall:
— be involved in review and acceptance of NDT procedures and NDT reports— be involved in calibration of NDT equipment and tools— do annual re-evaluation of the operators qualifications— be responsible for developing, verifying and/or approving the NDT procedures
in use and make sure these procedures are in compliance with the rules.
VT inspectors Visual testing shall be carried out by the builder’s qualified personnel before anyother NDT is applied, and meet the requirements given herein.
1.5 Basic requirements
1.5.1 The rules are based on the following conditions:Weld joint typesThe following main weld joints are covered, see the Figures in Sec.5:
— butt joints— T-joints (with and without full penetration)— fillet welds.
Types of imperfectionsThe main types of imperfections in fusion welding are given in EN ISO 6520-1 Welding and Allied Processes –Classification of Geometric Imperfections in Metallic materials - Part 1: Fusion Welding.Testing methodsFor detection of surface imperfections the following methods applies:
For the choice of applicable test methods, see DNVGL-CG-0051.
1.5.2 The test method selected shall in a reliable way be capable of detecting external and/or internaldefects present. Where necessary, this shall be achieved by using two or more test methods in combination.The particular test method(s) to be used shall be stated in the inspection plan.
1.5.3 Preparation and cleaning of welds for subsequent NDT shall be in accordance with the approved NDTprocedures.
1.5.4 When heat treatment is performed, the final NDT shall be carried out when all heat treatments havebeen completed.
Part 2 Chapter 4 Section 7
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 95Fabrication and testing
DNV GL AS
1.5.5 Final NDT of a weld shall not be commenced until the minimum delay time after welding as given inTable 2.
Table 2 Delay time requirements
Material grade Minimum delay time after welding 1) 2) [h]
VL 420 up to VL 690 48
VL 690 and higher 721) A longer interval and/or additional random inspection at a later period may be required.2) The 72-hour interval may be reduced to 48 hours for radiographic testing (RT, RT-D, RT-S, RT-CR) or ultrasonic testing(UT, PAUT, TOFD) inspection, provided there is no indication of delayed cracking, and a complete visual and randommagnetic particle (MT) or penetrant testing (PT) inspection to the satisfaction of the Society is conducted 72 hours afterwelds have been completed and cooled to ambient temperature.
1.5.6 Regardless of yield strength, a delayed inspection may be required where evidence of delayed crackinghas been observed in production welds.
1.5.7 The requirement for the delay period after post weld heat treatment may be relaxed, subject toagreement with the Society.
2 Non-destructive testing procedures and reports
2.1 General
2.1.1 NDT shall be performed in accordance with related procedures approved by the Society. Theprocedures shall be in accordance with DNVGL-CG-0051. Other recognised standards may be accepted basedon case-by-case approval.The NDT supplier shall produce the written procedures for the NDT applied. The procedures shall be verifiedby the NDT supplier’s level 3 before submission for approval. The NDT procedures shall define all relevantinformation relating to the inspection, including defect evaluation against acceptance criteria in accordancewith the relevant rules.NDT procedures for advanced NDT (e.g. RT-D, PAUT and TOFD) shall be qualified through procedurequalification test before being approved, see [2.7].
2.1.2 Unless otherwise agreed, NDT reports shall be signed by the NDT operator performing the testing.
2.1.3 Particular requirements and details listed in the report shall be in accordance with the approved NDTprocedures.
2.2 Visual testing
2.2.1 Unless otherwise agreed, VT shall be completed before other NDT methods are applied.
2.3 Magnetic particle testing
2.3.1 Where possible, both sides of the welds shall be tested. Magnetic particle testing (MT) shall be appliedfor welds in ferro-magnetic materials if not otherwise agreed.
Part 2 Chapter 4 Section 7
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 96Fabrication and testing
DNV GL AS
2.4 Radiographic testing
2.4.1 For radiographic testing, X-ray source shall be used whenever possible. Gamma-ray sources maybe used when qualified through examination by the Society. Radiographic testing (RT) may be replaced byultrasonic testing and vice versa, when justifiable and in agreement with the Society.
2.4.2 Processing and storage shall be such that the radiographs maintain their quality throughout the agreedstorage time. The radiographs shall be free from imperfections due to processing.
2.4.3 Imperfections suspected to be planar and discovered by RT shall be type determined, located and sizedby UT.
2.5 Ultrasonic testing
2.5.1 Ultrasonic testing (UT) shall not be carried out on welds with thickness < 10 mm unless qualified andaccepted down to and including 8 mm.
2.6 Penetrant testing
2.6.1 Where possible, both sides of the welds shall be tested. Penetrant testing (PT) shall only be applied forwelds in non-ferromagnetic materials if not otherwise agreed.
2.7 Advanced NDT
2.7.1 Technique and procedure qualification for ANDT shall be in accordance with DNVGL-CG-0051. Thedemonstration process onsite shall be witnessed by the Society.
3 Personnel qualifications
3.1 General
3.1.1 Except for VT, all NDT testing shall be carried out by qualified and certified personnel. The NDToperators and supervisors shall be certified according to a third party certification scheme based on ISO9712:2012 (or later version). Alternatively, personnel qualification to an employer based qualificationscheme as e.g. ASNT central certification program (ACCP). SNT-TC-1A, 2016 or ANSI/ASNT CP-189, 2016may be accepted if the NDT company's supplier's written practice is reviewed and found acceptable by theSociety. The NDT supplier’s written practice shall as a minimum, except for the impartiality requirements of acertification body and/or authorised body, comply with ISO 9712:2012.
3.1.2 The supervisors' and operators' certificates and competence shall comprise all industrial sectors andtechniques being applied by the NDT supplier.
3.1.3 VT shall be carried out by qualified personnel. The qualifications shall be documented by the builder.
3.1.4 Level 3 personnel shall be certified by an accredited certification body.
Part 2 Chapter 4 Section 7
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 97Fabrication and testing
DNV GL AS
3.2 NDT operatorsThe operator carrying out the NDT and interpreting indications (except for VT), shall as a minimum, bequalified and certified to level 2 in the NDT method(s) and industrial sector concerned as described in Sec.2[3.1.1]. See further details in DNVGL-CG-0051. However, operators only undertaking the gathering of datausing any NDT method and not performing data interpretation or data analysis may be qualified and certifiedas appropriate, at level 1.The operator shall have adequate knowledge of materials, weld, structures or components, NDT equipmentand limitations that are sufficient to apply the relevant NDT method for each application appropriately.
3.3 NDT supervisorsThe supervisor shall be available for scheduling and monitoring the performed NDT. The supervisor shallbe available for developing, verifying and/or approving the NDT procedures in use and make sure theseprocedures are in compliance with the applicable rules and standards. NDT supervisors shall, unlessotherwise agreed, be certified Level 3 in the testing method and industrial sector concerned.The supplier shall have a supervisor or supervisors, who is responsible for the appropriate execution ofNDT operations and for the professional standard of the operators and their equipment, including theprofessional administration of the working procedures. The supplier shall employ, on a full-time basis, atleast one supervisor independently certified to level 3 in the method(s) concerned as per the requirementsof item Sec.2 [3.1]. It is not permissible to appoint level 3 personnel, they shall be certified by an accreditedcertification body. It is recognised that a supplier may not directly employ a level 3 in all the stated methodspractised. In such cases, it is permissible to employ an external, independently certified, level 3 in thosemethods not held by the full-time level 3(s) of the supplier.The supervisor shall be involved in review and acceptance of NDT procedures, NDT reports, calibration ofNDT equipment and tools. The supervisor shall on behalf of the supplier re-evaluate the qualification of theoperators annually.
Guidance note:Welding supervisors with tasks and responsibilities for welding inspection according to ISO 14731 may be recognized in way ofthe DNV GL welding workshop approval also as supervisors for NDT based on additional NDT training and qualification. Personnelqualifications shall be verified by certification.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
4 NDT equipment
4.1 GeneralThe supplier shall maintain records of the NDT equipment used and detail information related tomaintenance, calibration and verification activities. If the supplier hires equipment, such equipment shallhave updated calibration records, and the operators shall be familiar with the specific equipment type priorto using it. Under any circumstance, the supplier shall possess sufficient equipment to carry out the servicesbeing a part of the NDT scope required by the Society.Where the equipment is of unique nature, the NDT operators shall be trained by competent personnel in theoperation and use of the equipment before carrying out NDT using this equipment.
Part 2 Chapter 4 Section 7
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 98Fabrication and testing
DNV GL AS
5 Extent of non-destructive testing
5.1 General
5.1.1 The extent of testing will depend on the type of vessel and the location of the joints.
5.1.2 The basic requirements for all vessel types are that all welds are subject to 100% visual testing carriedout by the builder’s qualified personnel before any other NDT is applied. In addition, welds shall be subjectedto testing with other test methods as given in the Table 3 below.The extent may be extended further depending on quality of welds and repair rate, see [6.2.2].The Society reserves the right to alter the test positions and/or to extend the scope of NDT against the NDTplan in case of doubts about proper workmanship.
5.1.3 The locations and areas to be examined shall be incorporated into the NDT plan. The NDT plan shallclearly identify the critical areas as defined below.
Table 3 Minimum non-destructive testing extent (in % of weld seam length) for structural welds
Testing methodArea Type of connection
MT/PT [%] 1) RT/UT [%] 2)
General areas
Butt welds and T-joints, full penetration
T-joints, partial penetration
Fillet welds
2
2
-
2
-
-
Deck/bottom platingwithin 0.4L amidship
Butt welds and T-joints, full penetration
T-joints, partial penetration
Fillet welds
5
5
-
5
-
-
Critical areas
Butt welds and T-joints, full penetration
T-joints, partial penetration
Fillet welds
20
20
20
20
-
-
Very thick structuralsteel in the upper hullof container ships4)
Butt welds and T-joints, full penetration
T-joints, partial penetration
Longitudinal oriented welds
Fillet welds
100
100
25
100
1003)
-
-
-
1) Only MT shall be applied for ferro magnetic materials. Duplex is not regarded as ferro magnetic material.2) RT shall not be applied for T-joints.3) UT shall be performed.4) Thickness range 50 < t ≤ 100 mm. Upper hull according to Pt.5 Ch.2 Sec.10 Figure 1.
Part 2 Chapter 4 Section 7
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 99Fabrication and testing
DNV GL AS
5.1.4 The different areas in Table 3 are defined as follow:Upper hull longitudinal structural members in container ships
— areas as given in Pt.5 Ch.2 Sec.10.
Critical areasAreas in way of critical load transfer points and large stress concentrations where a failure will endanger thesafety of the vessel, such as:
— stress concentrations in rudders or intersection between rudder structure and hull— for twin hull vessels stress concentrations in way of connections between hull and wet deck— deck beams in open hatch container ships— strength deck plating at outboard corners of cargo hatch openings in container carriers and other vesselswith similar hatch opening configuration
— other areas where the likelihood of occurrence of detrimental defects is considered to be extra high.
Guidance note:Areas to be considered for classification under this item are:
— welds produced by welding methods which the yard has little or no user experience
— welds produced by high heat input (> 50 kJ/cm) welding methods
— welds in large thickness (> 50 mm).
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
Deck and bottom plating within 0.4 L amidship:
— sheer strake at strength deck— stringer plate in strength deck— deck strake at longitudinal bulkhead— strength deck plating at corners of cargo hatch openings in bulk carriers, ore carriers, combinationcarriers and other vessels with similar hatch opening configuration
— bilge strake— longitudinal hatch coamings of length greater than 0.15 L— end brackets and deck house transition of longitudinal cargo hatch coamings— all watertight bulkheads independent of location.
Guidance note:For vessels with no clearly defined strength deck e.g. cruise ships, the above extents shall be applied to the decks contributingmost to the hull strength.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
General areasAreas not mentioned above.
5.1.5 NDT shall cover start and stop points of automatically welded seams, except for internal stiffenerswhere the extent of testing shall be agreed with the Society. Extent is as given in Table 3.
6 Acceptance criteria for non-destructive testing
6.1 General
6.1.1 All welds shall show evidence of good workmanship. For NDT acceptance criteria Table 4 applies:
Part 2 Chapter 4 Section 7
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 100Fabrication and testing
DNV GL AS
Table 4 Acceptance criteria for non-destructive testing
Testing method Symbol All vessels
Container vessels
(upper hull longitudinalstructural members,critical areas and deckand bottom plating
within 0.4 L amidships)
IACS Rec. 47 1, 2)Visual testing VT
ISO 5817 level C 2) ISO 5817 level B
Magnetic particle testing MT 3) ISO 23278 level 2x5)
Penetrant testing PT 3) ISO 23277 level 2x5)
Radiographic testing RT 3) ISO 10675 level 2 2)5) ISO 10675 level 15)
Ultrasonic testing 4) UT 3) ISO 11666 level 3 2)5) ISO 11666 level 25)6)
1) IACS Rec. No.47 may be applied for imperfections in finished welds. Alternatively, and for all other imperfections notdefined in IACS Rec. No.47, ISO 5817 level B or C applies
2) the Society may require higher acceptance criteria e.g. ISO 5817 level B for critical areas, and deck and bottomplating within 0.4 L amidships
3) regarding use of ISO 5817 and quality level for RT, UT, MT and PT, correlation is given in EN ISO 176354) all imperfections from which the reflected echo amplitude exceeds the evaluation level shall be characterized, and all
that are characterized as planar e.g. cracks, lack of fusion, incomplete penetration shall be rejected5) it is the measured size of the imperfection(s) that forms conventional basis for acceptance or rejection6) for upper hull longitudinal structural members in container ships under the regime of increased sensitivity testing,
all defects with a length of 20 mm or longer shall be rejected regardless of type.
6.1.2 Welds tested and accepted by the builder/manufacturer shall be verified if deemed necessary by theSociety.
6.1.3 Welds in aluminium shall comply with ISO 10042 level B (in critical areas, and in deck and bottomplating within 0.4 L amidship) or level C (in general areas). Regarding use of ISO 10042 and quality level forRT, UT and PT, correlation is given in ISO 17635 (ISO 10675-2), the same way as described for ISO 5817above.
6.1.4 Regarding use of ISO 10042 and quality level for RT (RT-F, RT-D), UT and PT, correlation is given inISO 17635 (ISO 10675-2), the same way as described for ISO 5817 above.
6.1.5 Relevant standard for TOFD is ISO 15626. Level B and level C of ISO 5817 are equal to, respectively,acceptance level 1 and level 2 of ISO 15626 (see correlation given in ISO 17635).
6.1.6 Relevant standard for PAUT is ISO 19285. Level B and level C of ISO 5817 are equal to, respectively,acceptance level 2 and level 3 of ISO 19285 (see correlation given in ISO 17635).
6.2 Non-conforming weldments
6.2.1 All indications (discontinuities) exceeding the applicable acceptance criteria shall be classed as defects,and shall be eliminated and repaired.
Part 2 Chapter 4 Section 7
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 101Fabrication and testing
DNV GL AS
6.2.2 If a non-conforming discontinuity is detected in a spot check test length during testing , the scopeof testing shall be extended (a spot check test length is typically 750 mm or 500 mm). Unless otherwiseagreed, the following apply:
— for each spot check test length with a detected non-conforming discontinuity two additional lengths of thesame weld shall be tested with the same method
— minimum length of the extension shall not be less than two times 500 mm for all methods except RT.Minimum additional test length for RT is two times the applied film length (minimum film length istypically 300 mm for hull welds)
— the additional testing shall be adjacent to the spot check test length where the non-conformingdiscontinuity was detected, one on each side
— where the length of the weld adjacent to the spot check test length is less than 500 mm, testing shallcover 100% of the relevant length
— extension may be waived where it is no doubt that a discontinuity is isolated and volumetric. The waiver isnot applicable for planar discontinuities, or continuous or semi-continuous discontinuities.
If systematically repeated non-conforming discontinuities are revealed, the extent of testing shall beincreased for welds manufactured under same conditions and where similar defects may be expected.
6.2.3 If non-conforming discontinuities are found to occur regularly, the reason for the non-conformingdiscontinuities shall be investigated. The WPS shall be reassessed before continuation of the welding.Necessary actions shall be taken to bring the production to the required quality level.
6.2.4 Detected non-conforming discontinuities shall be repaired unless they are found acceptable by theSociety. Removal of weld discontinuities and repair shall be performed in accordance with a procedureapproved by the Society.
6.2.5 After repair welding has been performed, the complete weld, (i.e. the repaired area plus minimum 100mm on each side) shall be subjected to at least the same NDT method(s) as specified for the original weld.
Part 2 Chapter 4 Section 7
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 102Fabrication and testing
DNV GL AS
SECTION 8 STRUCTURAL AND TIGHTNESS TESTING
1 General
1.1 Scope
1.1.1 This section specifies general requirements for structural and tightness testing of tanks and holds of:
— new vessels prior to delivery— structures involved in, or affected by, conversions or repairs.
See IACS UR S14 for definition of applicable ships.
1.1.2 General certification requirements are given in Sec.1 [3.1].
1.1.3 Documentation requirements are given inSec.1 [3.2].
1.1.4 The requirements in this section are not applicable for high speed light crafts and naval vessels.
1.2 Testing requirements
1.2.1 The testing procedures of watertight compartments shall be carried out in accordance with [2] and[3]. The requirements are divided into two parts:
— SOLAS Ships (including CSR BC & OT)— non-SOLAS Ships and SOLAS Exempt/Equivalent Ships.
1.2.2 Testing procedures of watertight compartments for SOLAS Ships (including CSR BC & OT) shall becarried out in accordance with [2], unless:
— a) the shipyard provides documentary evidence of the shipowner’s agreement to a request to the flagadministration for an exemption from the application of SOLAS Chapter II-1, Regulation 11, or for anequivalency agreeing that the content of [3] is equivalent to SOLAS Chapter II-1, Regulation 11; and
— b) the above-mentioned exemption/equivalency has been granted by the responsible flag administration.
1.2.3 Testing procedures of watertight compartments shall be carried out in accordance with [3] for non-SOLAS ships and those SOLAS ships (including CSR BC & OT) for which:
— a) the shipyard provides documentary evidence of the shipowner’s agreement to a request to the flagadministration for an exemption from the application of SOLAS Chapter II-1, Regulation 11, or for anequivalency agreeing that the content of [3] is equivalent to SOLAS Chapter II-1, Regulation 11; and
— b) the above-mentioned exemption/equivalency has been granted by the responsible flag administration.
Part 2 Chapter 4 Section 8
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 103Fabrication and testing
DNV GL AS
2 Procedures for testing tanks and tight boundaries - SOLAS ships
2.1 General
2.1.1 These test procedures shall confirm the watertightness of tanks and watertight boundaries and thestructural adequacy of tanks which consist of the watertight subdivisions of ships. These procedures may alsobe applied to verify the weathertightness of structures and shipboard outfitting. The tightness of all tanksand watertight boundaries of ships during new construction and those relevant to major conversions or majorrepairs is to be confirmed by these test procedures prior to the delivery of the ship.
Guidance note:
— Watertight subdivision means the transverse and longitudinal subdivisions of the ship required to satisfy the subdivisionrequirements of SOLAS Chapter II-1.
— Major repair means a repair affecting structural integrity.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
2.2 Application
2.2.1 All gravity tanks and other boundaries required to be watertight or weathertight shall be tested inaccordance with this procedure and proven to be tight and structurally adequate as follows:
1) gravity tanks for their tightness and structural adequacy,2) watertight boundaries other than tank boundaries for their watertightness, and3) weathertight boundaries for their weathertightness.
Guidance note:Gravity tank means a tank that is subject to vapour pressure not greater than 70 kPa.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
2.2.2 The testing of cargo containment systems of liquefied gas carriers shall be in accordance with thetesting requirements in 4.21 to 4.26 of the IGC Code and standards deemed appropriate by DNV GL.
2.2.3 The testing of structures not listed in Table 2 or Table 3 shall be specially considered.
2.3 Test types and definitions
2.3.1 The following two types of tests are specified in this requirement:
— Structural test: a test to verify the structural adequacy of tank construction. This may be a hydrostatictest or, where the situation warrants, a hydropneumatic test.
— Leak test: a test to verify the tightness of a boundary. Unless a specific test is indicated, this may be ahydrostatic/hydropneumatic test or an air test. A hose test may be considered an acceptable form of leaktest for certain boundaries, as indicated by footnote 3 of Table 2.
Part 2 Chapter 4 Section 8
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 104Fabrication and testing
DNV GL AS
2.3.2 The definition of each test type is as follows:
Table 1 Definitions
Term Definition
hydrostatic test
(leak and structural)a test wherein a space is filledwith a liquid to a specified head
hydropneumatic test
(leak and structural)a test combining a hydrostatic test and an air test, wherein a space is partially filled with aliquid and pressurized with air
hose test
(leak)a test to verify the tightness of the joint by a jet of water with the joint visible from theopposite side
air tests
(leak)
a test to verify the tightness by means of air pressure differential and leak indicatingsolution. It includes tank air tests and joint air tests, such as a compressed air fillet weldtests and vacuum box tests
compressed air fillet weldtest
(leak)an air test of a fillet welded T-joint with a leak indicating solution applied on the fillet welds
vacuum box test
(Leak)a box over a joint with leak indicating solution applied on the fillet or butt welds. A vacuumiscreated inside the box to detect any leaks
ultrasonic test
(leak)a test to verify the tightness of a sealing of closing devices such as hatch covers by means ofultrasonic detection techniques
penetration test
(leak)
a test to verify that no visual dye penetrant indications of potential continuous leakagesexist in the boundaries of a compartment by means of low surface tension liquids (i.e. dyepenetrant test)
2.4 Test procedures2.4.1 GeneralTests shall be carried out in the presence of a surveyor at a stage sufficiently close to the completion ofwork with all hatches, doors, windows, etc., installed and all penetrations including pipe connections fitted,and before any ceiling and cement work is applied over the joints. Specific test requirements are given in[2.4.4] and Table 2. For the timing of the application of coating and the provision of safe access to joints, see[2.4.5], [2.4.6] and Table 4.
2.4.2 Structural test procedures
2.4.2.1 Type and time of testWhere a structural test is specified in Table 2 or Table 3, a hydrostatic test in accordance with [2.4.4.1] willbe acceptable. Where practical limitations (strength of building berth, light density of liquid, etc.) preventthe performance of a hydrostatic test, a hydropneumatic test in accordance with [2.4.4.2] may be acceptedinstead.A hydrostatic test or hydropneumatic test for the confirmation of structural adequacy may be carried outwhile the vessel is afloat, provided the results of a leak test are confirmed to be satisfactory before the vesselis afloat.
Part 2 Chapter 4 Section 8
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 105Fabrication and testing
DNV GL AS
2.4.2.2 Testing schedule for new construction or major structural conversion
1) Tanks which are intended to hold liquids, and which form part of the watertight subdivision of the ship,shall be tested for tightness and structural strength as indicated in Table 2 and Table 3.
2) The tank boundaries shall be tested from at least one side. The tanks for structural test shall be selectedso that all representative structural members are tested for the expected tension and compression.
3) The watertight boundaries of spaces other than tanks for structural testing may be exempted, providedthat the water-tightness of boundaries of exempted spaces is verified by leak tests and inspections.Structural testing may not be exempted and the requirements for structural testing of tanks in [2.4.2.1].to [2.4.2.2]) shall apply, for ballast holds, chain lockers and a representative cargo hold if intended forin-port ballasting.
4) Tanks which do not form part of the watertight subdivision of the ship, may be exempted from structuraltesting provided that the water-tightness of boundaries of exempted spaces is verified by leak tests andinspections.Guidance note:Watertight subdivision means the main transverse and longitudinal subdivisions of the ship required to satisfy the subdivisionrequirements of SOLAS Chapter II-1.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
2.4.3 Leak test proceduresFor the leak tests specified in Table 2, tank air tests, compressed air fillet weld tests, vacuum box testsin accordance with [2.4.4.4] through [2.4.4.6], or their combination, will be acceptable. Hydrostatic orhydropneumatic tests may also be accepted as leak tests provided that [2.4.4.5], [2.4.5], [2.4.6] and [2.4.7]are complied with. Hose tests will also be acceptable for such locations as specified in Table 2, Footnote 3, inaccordance with [2.4.4.3].The application of the leak test for each type of welded joint is specified in Table 4.Air tests of joints may be carried out in the block stage provided that all work on the block that may affectthe tightness of a joint is completed before the test. See also [2.4.5.1] for the application of final coatingsand [2.4.6] for the safe access to joints and the summary in Table 4.
2.4.4 Test methods
2.4.4.1 Hydrostatic testUnless another liquid is approved, hydrostatic tests shall consist of filling the space with fresh water or seawater, whichever is appropriate for testing, to the level specified in Table 2 or Table 3. See also [2.4.7].In cases where a tank is designed for cargo densities greater than sea water and testing is with fresh wateror sea water, the testing pressure height shall simulate the actual loading for those greater cargo densities asfar as practicable.All external surfaces of the tested space shall be examined for structural distortion, bulging and buckling,other related damage and leaks.
2.4.4.2 Hydropneumatic testHydropneumatic tests, where approved, shall be such that the test condition, in conjunction with theapproved liquid level and supplemental air pressure, will simulate the actual loading as far as practicable. Therequirements and recommendations for tank air tests in [2.4.4.4] will also apply to hydropneumatic tests.See also [2.4.7].All external surfaces of the tested space shall be examined for structural distortion, bulging and buckling,other related damage and leaks.
2.4.4.3 Hose testHose tests shall be carried out with the pressure in the hose nozzle maintained at least at 2·105 Pa during thetest. The nozzle shall have a minimum inside diameter of 12 mm and be at a perpendicular distance from thejoint not exceeding 1.5 m. The water jet shall impinge directly upon the weld.
Part 2 Chapter 4 Section 8
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 106Fabrication and testing
DNV GL AS
Where a hose test is not practical because of possible damage to machinery, electrical equipment insulationor outfitting items, it may be replaced by a careful visual examination of welded connections, supportedwhere necessary by means such as a dye penetrant test or ultrasonic leak test or the equivalent.
2.4.4.4 Tank air testAll boundary welds, erection joints and penetrations, including pipe connections, shall be examined inaccordance with approved procedure and under a stabilized pressure differential above atmospheric pressurenot less than 0.15·105 Pa, with a leak indicating solution such as soapy water/detergent or a proprietarybrand applied.A U-tube with a height sufficient to hold a head of water corresponding to the required test pressure shallbe arranged. The cross sectional area of the U-tube is not to be less than that of the pipe supplying airto the tank. Arrangements involving the use of two calibrated pressure gauges to verify the required testpressure may be accepted taking into account the provisions in F5.1 and F7.4 of IACS Recommendation 140,"Recommendation for Safe Precautions during Survey and Testing of Pressurized Systems".A double inspection shall be made of tested welds. The first shall be carried out immediately upon applyingthe leak indication solution. The second shall be carried out after approximately four to five minutes in orderto detect those smaller leaks which take time to appear.
2.4.4.5 Compressed air fillet weld testIn this air test, compressed air is injected from one end of a fillet welded joint and the pressure verified atthe other end of the joint by a pressure gauge. Pressure gauges shall be arranged so that an air pressure ofat least 0.15·105 Pa can be verified at each end of all passages within the portion being tested.
Note:Where a leak test is required for fabrication involving partial penetration welds, a compressed air test is also to be applied in thesame manner as to fillet weld where the root face is large, i.e., 6-8 mm.
---e-n-d---o-f---n-o-t-e---
2.4.4.6 Vacuum box testA box (vacuum testing box) with air connections, gauges and an inspection window is placed over the jointwith a leak indicating solution applied to the weld cap vicinity. The air within the box is removed by an ejectorto create a vacuum of 0.20·105 - 0.26·105 Pa inside the box.
2.4.4.7 Ultrasonic testAn ultrasonic echo transmitter shall be arranged inside of a compartment and a receiver shall be arrangedon the outside. The watertight/weathertight boundaries of the compartment are scanned with the receiver inorder to detect an ultrasonic leak indication. A location where sound is detectable by the receiver indicates aleakage in the sealing of the compartment.
2.4.4.8 Penetration testA test of butt welds or other weld joints uses the application of a low surface tension liquid at one side ofa compartment boundary or structural arrangement. If no liquid is detected on the opposite sides of theboundaries after the expiration of a defined period of time, this indicates tightness of the boundaries. Incertain cases, a developer solution may be painted or sprayed on the other side of the weld to aid leakdetection.
2.4.4.9 Other testOther methods of testing may be considered upon submission of full particulars prior to the commencementof testing.
2.4.5 Application of coating
2.4.5.1 Final coatingFor butt joints welded by an automatic process, the final coating may be applied any time before thecompletion of a leak test of spaces bounded by the joints, provided that the welds have been carefullyinspected visually to the satisfaction of the surveyor.
Part 2 Chapter 4 Section 8
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 107Fabrication and testing
DNV GL AS
Surveyors reserve the right to require a leak test prior to the application of final coating over automaticerection butt welds.For all other joints, the final coating is to be applied after the completion of the leak test of the joint. See alsoTable 4.
2.4.5.2 Temporary coatingAny temporary coating which may conceal defects or leaks shall be applied at the time as specified for thefinal coating (see [2.4.5.1]). This requirement does not apply to shop primer.
2.4.6 Safe access to jointsFor leak tests, safe access to all joints under examination shall be provided. See also Table 4.
2.4.7 Hydrostatic or hydropneumatic tightness testIn cases where the hydrostatic or hydropneumatic tests are applied instead of a specific leak test, examinedboundaries shall be dew-free, otherwise small leaks are not visible.
2.5 Test requirements for tanks and boundariesTable 2
Tank or boundary to be tested Test type Test head or pressure Remarks
1 Double bottom tanks4 Leak andstructural1
The greater of :
— top of the overflow,— to 2.4 m above top of tank2,
or— to bulkhead deck.
2 Double bottom voids5 Leak See [2.4.4.4] through [2.4.4.6],as applicable.
Including pumproom doublebottom andbunker tankprotection doublehull required byMARPOL Annex I.
3 Double side tanks Leak andstructural1
The greater of:
— top of the overflow,— to 2.4 m above top of tank2,
or— to bulkhead deck.
4 Double side voids Leak See [2.4.4.4] through [2.4.4.6],as applicable.
5 Deep tanks other than those listedelsewhere in this table
Leak andstructural1
The greater of:
— top of the overflow, or— to 2.4 m above top of tank2 .
Part 2 Chapter 4 Section 8
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 108Fabrication and testing
DNV GL AS
6 Cargo oil tanks Leak andstructural1
The greater of:
— top of the overflow,— to 2.4 m above top of tank2,
or— to top of tank2 plus— setting of any pressure relief
valve.
7 Ballast holds of bulk carriers Leak andstructural1 Top of cargo hatch coaming.
8 Peak tanks Leak andstructural1
The greater of:
— top of the overflow, or— to 2.4 m above top of tank2.
Aft peak to betested afterinstallation ofstern tube.
.1 Fore peak spaces with equipment Leak See [2.4.4.3] through [2.4.4.6],as applicable.
.2 Fore peak voids Leak See [2.4.4.4] through [2.4.4.6],as applicable.
.3 Aft peak spaces with equipment Leak See [2.4.4.3] through [2.4.4.6],as applicable.
9
.4 Aft peak voids Leak See [2.4.4.4] through [2.4.4.6],as applicable.
Aft peak to betested afterinstallation ofstern tube.
10 Cofferdams Leak See [2.4.4.4]through [2.4.4.6],as applicable.
.1 Watertight bulkheads Leak8 See [2.4.4.3] through [2.4.4.6],as applicable7 .
11
.2 Superstructure end bulkheads Leak See [2.4.4.3] through [2.4.4.6],as applicable.
12 Watertight doors below freeboard orbulkhead deck and watertight hatch covers Leak6, 7 See [2.4.4.3] through [2.4.4.6],
as applicable.
13 Double plate rudder blades Leak See [2.4.4.4] through [2.4.4.6],as applicable.
14 Shaft tunnels clear of deep tanks Leak3 See [2.4.4.3] through [2.4.4.6],as applicable.
15 Shell doors Leak3 See [2.4.4.3] through [2.4.4.6],as applicable.
16 Weathertight hatch covers, and closingappliances Leak3, 7 See [2.4.4.3] through [2.4.4.6],
17 Dual purpose tanks/dry cargo hatch covers Leak3, 7 See [2.4.4.3] through [2.4.4.6],as applicable.
In addition tostructural test initem 6 or 7.
Part 2 Chapter 4 Section 8
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 109Fabrication and testing
DNV GL AS
18 Chain lockers Leak andstructural1 Top of chain pipe.
19 L.O. sump. tanks and other similar tanks/spaces under main engines Leak9 See [2.4.4.3] through [2.4.4.6],
as applicable.
20 Ballast ducts Leak andstructural1
The greater of:
— ballast pump maximumpressure, or
— setting of any pressure reliefvalve.
21 Fuel oil tanks Leak andstructural1
The greater of:
— top of the overflow,— to 2.4 m above top of tank2,
or— to top of tank2 plus— setting of any pressure relief
valve.
1) See section [2.4.2.2].2) The top of a tank is the deck forming the top of the tank, excluding any hatchways.3) Hose test may also be considered as a medium of the test. See [2.3.2].4) Including tanks arranged in accordance with the provisions of SOLAS regulation II-1/9.4.5) Including duct keels and dry compartments arranged in accordance with the provisions of SOLAS regulation
II-1/11.2 and II-1/9.4 respectively, and/or oil fuel tank protection and pump room bottom protection arrangedin accordance with the provisions of MARPOL Annex I, Chapter 3, Part A regulation 12A and Chapter 4, Part A,regulation 22 respectively.
6) Where water tightness of a watertight door has not been confirmed by prototype test, testing by filling watertightspaces with water shall be carried out. See SOLAS regulation II-1/16.2 and MSC/Circ.1176.
7) As an alternative to the hose testing, other testing methods listed in [2.4.4.7] through [2.4.4.9] may be applicablesubject to adequacy of such testing methods being verified. See SOLAS regulation II-1/11.1. For watertightbulkheads (item 11.1) alternatives to the hose testing may only be used where a hose test is not practicable.
8) A Leak and structural test, see [2.4.2.2] shall be carried out for a representative cargo hold if intended for in-portballasting. The filling level requirement for testing cargo holds intended for in-port ballasting shall be the maximumloading that will occur in-port as indicated in the loading manual.
9) Where L.O. sump tanks and other similar spaces under main engines intended to hold liquid form part of thewatertight subdivision of the ship, they shall be tested as per the requirements of item 5, Deep tanks other thanthose listed elsewhere in this table.
Guidance note:See Pt.3 Ch.12 Sec.1 [3.3.3] for test requirements related to doors and hatch covers which become immersed by an equilibriumor an intermediate water plane in a damaged condition.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
2.5.1 Additional test requirements for special service ships/tanks
Table 3
Type of ship/tank Structuresto be tested Type of test Test head or pressure Remarks
1 Liquefied gas carriers Integral tanks Leak andstructural See UR G1
Part 2 Chapter 4 Section 8
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 110Fabrication and testing
DNV GL AS
Type of ship/tank Structuresto be tested Type of test Test head or pressure Remarks
Hull structuresupportingmembrane or semi-membrane tanks
3 Chemical carriersIntegral orindependent cargotanks
Leak andstructural1
The greater of:
— to 2.4 m above top oftank2, or
— to top of tank2 plus— setting of any pressure
relief valve.
Where a cargotank is designedfor the carriageof cargoes withspecific gravitieslarger than 1.0,an appropriateadditionalhead shall beconsidered.
1) See section [2.4.2.2].2) Top of tank is deck forming the top of the tank excluding any hatchways.
2.5.2 Application of leak test, coating and provision of safe access for type of welded joints
Table 4
Coating1 Safe access2
Type of welded joints Leak testBefore leak test
After leak testbut before
structural testLeak test Structural
test
Automatic Not required Allowed3 N/A Not required Not required
Butt Manual or
semi-automatic4Required Not allowed Allowed Required Not required
FilletAutomatic,
semi-automaticor manual
Required Not allowed Allowed Required Not required
Part 2 Chapter 4 Section 8
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 111Fabrication and testing
DNV GL AS
1) coating refers to internal (tank/hold coating), where applied, and external (shell/deck) painting. It does not refer toshop primer
2) temporary means of access for verification of the leak test3) the condition applies provided that the welds have been carefully inspected visually to the satisfaction of the
surveyor4) flux core arc welding (FCAW) semi-automatic butt welds need not be tested provided that careful visual inspections
show continuous uniform weld profile shape, free from repairs, and the results of NDE testing show no significantdefects.
3 Procedures for testing tanks and tight boundaries - Non-SOLASships and SOLAS exemption/equivalent ships
3.1 General
3.1.1 These test procedures shall confirm the watertightness of tanks and watertight boundaries and thestructural adequacy of tanks which consist of the watertight subdivisions of ships. These procedures may alsobe applied to verify the weathertightness of structures and shipboard outfitting. The tightness of all tanksand watertight boundaries of ships during new construction and those relevant to major conversions or majorrepairs shall be confirmed by these test procedures prior to the delivery of the ship.
Guidance note:
— Watertight subdivision means the transverse and longitudinal subdivisions of the ship required to satisfy the subdivisionrequirements of SOLAS Chapter II-1.
— Major repair means a repair affecting structural integrity.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
3.2 Application
3.2.1 Testing procedures shall be carried out in accordance with the requirements of [2] in association withthe following alternative procedures for [2.4.2.2] Testing schedule for new construction or major structuralconversion and alternative test requirements for Table 2 in [2.5].
3.2.2 The tank boundaries shall be tested from at least one side. The tanks for structural test shall beselected so that all representative structural members are tested for the expected tension and compression.
3.2.3 Structural tests shall be carried out for at least one tank of a group of tanks having structuralsimilarity (i.e. same design conditions, alike structural configurations with only minor localised differencesdetermined to be acceptable by the attending surveyor) on each vessel provided all other tanks are testedfor leaks by an air test. The acceptance of leak testing using an air test instead of a structural test does notapply to cargo space boundaries adjacent to other compartments in tankers and combination carriers or tothe boundaries of tanks for segregated cargoes or pollutant cargoes in other types of ships.
3.2.4 Additional tanks may require structural testing if found necessary after the structural testing of thefirst tank.
3.2.5 Where the structural adequacy of the tanks of a vessel were verified by the structural testing requiredin Table 2, subsequent vessels in the series (i.e. sister ships built from the same plans at the same shipyard)may be exempted from structural testing of tanks, provided that:
1) water-tightness of boundaries of all tanks is verified by leak tests and thorough inspections are carriedout.
Part 2 Chapter 4 Section 8
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 112Fabrication and testing
DNV GL AS
2) structural testing is carried out for at least one tank of each type among all tanks of each sister vessel.3) additional tanks may require structural testing if found necessary after the structural testing of the first
tank or if deemed necessary by the attending surveyor.
For cargo space boundaries adjacent to other compartments in tankers and combination carriers orboundaries of tanks for segregated cargoes or pollutant cargoes in other types of ships, the provisions ofparagraph [3.2.3] shall apply in lieu of paragraph [3.2.5] 2).
3.2.6 Sister ships built (i.e. keel laid) two years or more after the delivery of the last ship of the series, maybe tested in accordance with [3.2.5] at the discretion of DNV GL, provided that:
1) general workmanship has been maintained (i.e. there has been no discontinuity of shipbuilding orsignificant changes in the construction methodology or technology at the yard, shipyard personnel areappropriately qualified and demonstrate an adequate level of workmanship as determined by DNV GL);and
2) an NDT plan is implemented and evaluated byDNV GL for the tanks not subject to structural tests.Shipbuilding quality standards for the hull structure during new construction shall be reviewed andagreed during the kick-off meeting. Structural fabrication shall be carried out in accordance with IACSRecommendation 47, "Shipbuilding and Repair Quality Standard", or a recognised fabrication standardwhich has been accepted by DNV GL prior to the commencement of fabrication/construction. The workshall be carried out in accordance with the Rules and under survey of DNV GL. Pa
rt 2 Chapter 4 Section 8
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 113Fabrication and testing
DNV GL AS
SECTION 9 HULL SURVEY FOR NEW CONSTRUCTION OF BULKCARRIERS AND OIL TANKERS
1 General
1.1 Application
1.1.1 The requirements in this section are applicable to tankers and bulk carriers subject to SOLAS ChapterII-1 Part A-1 Regulation 3-10, Goal-based ship construction standards for bulk carriers and oil tankers.
1.1.2 Reference is made to IACS UR Z23, Hull Survey for New Construction, Appendix 2.
2 Examination and test plan for newbuilding activities
2.1 Requirements
2.1.1 The shipbuilder shall provide plans of the items which are intended to be examined and tested inaccordance with the Society's rules in the survey plan, taking into account the ship type and design. Thissurvey plan shall be reviewed at the time of the kick off meeting, and shall include:
1) A set of requirements, including specifying the extent and scope of the construction survey(s) andidentifying areas that need special attention during the survey(s), to ensure compliance of constructionwith mandatory ship construction standards including:
— types of surveys (visual, non-destructive examination, etc.) depending on location, materials,welding, casting, coatings, etc.
— establishment of a construction survey schedule for all assembly stages from the kick-off meeting,through all major construction phases, up to delivery
— inspection plan, including provisions for critical areas identified during design approval— criteria for acceptance— interaction with shipyard, including notification and documentation of survey results— correction procedures to remedy construction defects— list of items that would require scheduling or formal surveys— determination and documentation of areas that need special attention throughout ship's life, includingcriteria used in making the determination.
2) A description of the requirements for all types of testing during survey, including test criteria.
3 Design transparency
3.1 General
3.1.1 For ships subject to compliance with IMO Res. MSC.287(87), IMO Res. MSC.290(87), IMO Res.MSC.296(87) and IMO MSC.1/Circ.1343, readily available documentation shall include the main goal-basedparameters and all relevant design parameters that may limit the operation of the ship.
Part 2 Chapter 4 Section 9
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 114Fabrication and testing
DNV GL AS
4 Ship construction file
4.1 General
4.1.1 A ship construction file (SCF) with specific information on how the functional requirements of the goal-based ship construction standards for bulk carriers and oil tankers have been applied in the ship designand construction shall be provided upon delivery of a new ship, and kept on board the ship and/or ashoreand updated as appropriate throughout the ship's service. The contents of the SCF shall conform to therequirements below.
4.2 Content of ship construction file
4.2.1 The following design specific information shall be included in SCF:
— areas requiring special attention throughout the ship's life (including critical structural areas)— all design parameters limiting the operation of a ship— any alternatives to the rules, including structural details and equivalency calculations— “as built” drawings and information which are verified to incorporate all alterations approved by therecognized organization or flag state during the construction process including scantling details, materialdetails, location of butts and seams, cross section details and locations of all partial and full penetrationwelds
— net (renewal) scantlings for all the structural constituent parts, as built scantlings and voluntary additionthicknesses
— minimum hull girder section modulus along the length of the ship which has to be maintained throughoutthe ship's life, including cross section details such as the value of the area of the deck zone and bottomzone, the renewal value for the neutral axis zone
— a listing of materials used for the construction of the hull structure, and provisions for documentingchanges to any of the above during the ship's service life
— copies of certificates of forgings and castings welded into the hull (see IACS UR W7 and UR W8)— details of equipment forming part of the watertight and weather tight integrity of the ship— tank testing plan including details of the test requirements (see IACS UR S14)— details for the bottom survey afloat, when applicable, information for divers, clearances measurementsinstructions etc., tank and compartment boundaries
— docking plan and details of all penetrations normally examined at dry docking— coating technical file, for ships subject to compliance with the IMO Performance Standard for ProtectiveCoatings (PSPC).
4.2.2 See Table 1 for details of information to be further included. This information has to be kept on boardthe ship and/or ashore and updated as appropriate throughout the ship's life in order to facilitate safeoperation, maintenance, survey, repair and emergency measures.
4.2.3 It shall be noted that parts of the content of the SCF may be subject to various degrees of restrictedaccess and that such documentation may be appropriately kept ashore.
4.2.4 The SCF has to include the list of documents constituting the SCF and all information listed in Table1, which is required for a ship's safe operation, maintenance, survey, repair and in emergency situations.Details of specific information that is not considered to be critical to safety might be included directly or byreference to other documents.
4.2.5 When developing an SCF, all of the columns in Table 1 have to be reviewed to ensure that all necessaryinformation has been provided.
Part 2 Chapter 4 Section 9
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 115Fabrication and testing
DNV GL AS
4.2.6 It may be possible to provide information listed in Table 1 under more than one Tier II functionalrequirement as a single item within the SCF, for example, the coating technical file required by the PSPC isrelevant for both coating life and survey during construction.
4.2.7 The SCF has to remain with the ship and, in addition, be available to its classification Society and flagstate throughout the ship's life. Where information not considered necessary to be on board is stored ashore,procedures to access this information should be specified in the onboard SCF. The intellectual propertyprovisions within the SCF should be duly complied with.
4.2.8 The SCF should be updated throughout the ship's life at any major event, including, but not limited to,substantial repair and conversion, or any modification to the ship structure.
Table 1 List of information to be included in the ship construction file
Tier II items Information to be includedFurtherexplanation ofthe content
Example documentsNormalstoragelocation
DESIGN
assumed design life in years SCF-specificonboardship
1 Design lifestatement ornote on midshipsection
midship section planonboardship
2 Environmentalconditions
assumed environmentalconditions
— statementreferencingdata source orrule (specificrule and data)or
— in accordancewith rule(date andrevision)
SCF-specificonboardship
3 Structural strength
applied rule (date andrevision) SCF-specific
onboardship
3.1 General design
applied alternative to rule
applied designmethodalternative torule and subjectstructure(s) capacity plan
onboardship
calculating conditions andresults
allowable loadingpattern loading manual
onboardship
3.2Deformationand failuremodes
assumed loading conditions
maximumallowable hullgirder bendingmoment andshear force
trim and stability bookletonboardship
Part 2 Chapter 4 Section 9
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 116Fabrication and testing
DNV GL AS
loading instrument instructionmanual
onboardship
operation and maintenance manualsonboardship
3.3 Ultimatestrength
operational restrictions due tostructural strength
minimum hull girder sectionmodulus along the length ofthe ship to be maintainedthroughout the ship’s life,including cross section detailssuch as the value of the areaof the deck zone and bottomzone, the renewal value forthe neutral axis zone
plan showinghighly stressedareas
(e.g. criticalstructural areas)prone to yieldingand/or buckling
general arrangement planonboardship
gross scantlings of structuralconstituent parts
structuraldrawings key construction plans
onboardship
rudder and sternframe rudder and rudder stock plans
onboardship
structural detailsonboardship
yard plansonshorearchive
net scantlings of structuralconstituent parts, as builtscantlings and voluntaryaddition thicknesses
structuraldetails of typicalmembers
dangerous area planonboardship
3.4 Safety margins
hull form
hull forminformationindicated in keyconstructionplans
lines plan
or
equivalent
onshorearchive
Part 2 Chapter 4 Section 9
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 117Fabrication and testing
DNV GL AS
hull form datastored withinan onboardcomputernecessary fortrim and stabilityand longitudinalstrengthcalculations
onboardship
applied rule (date andrevision)
applied alternative to rule
applied designmethodalternative torule and subjectstructures
SCF-specificonboardship
calculating conditions andresults;
assumed loading conditions
assumed loadingconditions andrates
structural detailsonboardship
bulky outputof fatigue lifecalculation
fatigue life calculationonshorearchive
4Fatigue life
fatigue life calculation results plan showingareas (e.g.critical structuralareas) prone tofatigue
areas prone to fatigueonboardship
5 Residualstrength
applied rule (date andrevision) SCF-specific
onboardship
6 Protection against corrosion
SCF-specificonboardship
6.1 Coating life
coated areas and targetcoating life and othermeasures for corrosionprotection in holds, cargo andballast tanks, other structure-integrated deep tanks andvoid spaces
coating technical file required byPSPC (performance standard forprotective coatings for dedicatedseawater ballast tanks in all typesof ships and double-side skinspaces of bulk carriers, adopted byIMO Resolution MSC.215(82), asamended and Performance standardfor protective coatings for cargo oiltanks of crude oil tankers, adoptedby IMO Resolution MSC.288(87), asamended)
onboardship
Part 2 Chapter 4 Section 9
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 118Fabrication and testing
DNV GL AS
specification for coating andother measures for corrosionprotection in holds, cargo andballast tanks, other structure-integrated deep tanks andvoid spaces
areas prone to excessive corrosiononboardship
gross scantlings of structuralconstituent parts
6.2 Corrosionaddition
net scantlings of structuralconstituent parts, as builtscantlings and voluntaryaddition thicknesses
key construction plansonboardship
7 Structuralredundancy
applied rule (date andrevision) SCF-specific
onboardship
applied rule (date andrevision) SCF-specific
onboardship
8Watertight andweathertightintegrity key factors for watertight and
weathertight integrity
details ofequipmentforming part ofthe watertightand weathertightintegrity
structural details of hatch covers,doors and other closings integralwith the shell and bulkheads
onboardship
9Humanelementconsiderations
list of ergonomic designprinciples applied to shipstructure design to enhancesafety during operations,inspections and maintenanceof ship
SCF-specificonboardship
— applied rule (date andrevision)
— applicable industrystandards for designtransparency and IPprotection
intellectual property provisionsonboardship
10 Designtransparency
reference to part of SCFinformation kept ashore
summary, location and accessprocedure for part of SCFinformation on shore
onboardship
CONSTRUCTION
11Constructionqualityprocedures
applied construction qualitystandard
recognizednational orinternationalconstructionquality standard
SCF-specificonboardship
Part 2 Chapter 4 Section 9
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 119Fabrication and testing
DNV GL AS
applied rules(date andrevision)
SCF-specificonboardshipsurvey regime applied
during construction (toinclude all owner and classscheduled inspections duringconstruction)
copies ofcertificates offorgings andcastings weldedinto the hull
tank testing planonboardship
non-destructive testing planonboardship
12 Survey duringconstruction
information on non-destructive examination
coating technical file required byPSPC
onboardship
IN-SERVICE CONSIDERATIONS
SCF-specificonboardshipmaintenance plans specific
to the structure of the shipwhere higher attention iscalled for
plan showinghighly stressedareas (e.g.critical structuralareas) proneto yielding,buckling, fatigueand/or excessivecorrosion
operation and maintenance manuals(e.g. hatch covers and doors)
onboardship
preparations for survey
arrangementand details ofall penetrationsnormallyexamined at dry-docking
docking planonboardship
gross hull girder sectionmodulus
details for dry-docking dangerous area plan
onboardship
ship structure access manualonboardship
means of access to other structure-integrated deep tanks
onboardship
minimum hull girder sectionmodulus along the length ofthe ship to be maintainedthroughout the ship’s life,including cross section detailssuch as the value of the areaof the deck zone and bottomzone, the renewal value forthe neutral axis zone
details for in-water survey
coating technical file required byPSPC
onboardship
13 Survey andmaintenance
gross scantlings of structuralconstituent parts key construction plans
onboardship
Part 2 Chapter 4 Section 9
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 120Fabrication and testing
DNV GL AS
rudder and rudder stockonboardship
structural detailsonboardship
yard plansonshorearchive
net scantlings of structuralconstituent parts, as builtscantlings and voluntaryaddition thicknesses
lines plan or equivalentonshorearchive
hull form
hull forminformationindicated in keyconstructionplans
onboardship
ship structure access manualonboardship
14 Structuralaccessibility
means of access to holds,cargo and ballast tanks andother structure-integrateddeep tanks
plans showingarrangement anddetails of meansof access means of access to other structure-
integrated deep tanks
onboardship
RECYCLING CONSIDERATIONS
15 Recycling
identification of allmaterials that were usedin construction and mayneed special handling dueto environmental and safetyconcerns
list of materialsused for theconstruction ofthe hull structure
SCF-specificonboardship
Part 2 Chapter 4 Section 9
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 121Fabrication and testing
DNV GL AS
Note:
1) SCF-specific means documents to be developed especially to meet the requirements of these GBS guidelines (MSC.1/Circ.1343)
2) key construction plans means plans such as midship section, main O.T. and W.T. transverse bulkheads, constructionprofiles/plans, shell expansions, forward and aft sections in cargo tank (or hold) region, engine-room construction, forwardconstruction and stern construction drawings
3) yard plans means a full set of structural drawings, which include scantling information of all structural members
4) hull form means a graphical or numerical representation of the geometry of the hull. Examples would include the graphicaldescription provided by a lines plan and the numerical description provided by the hull form data stored within an onboardcomputer
5) lines plan means a special drawing which is dedicated to show the entire hull form of a ship
6) equivalent (to lines plan) means a set of information of hull form to be indicated in key construction plans for SCF purposes.Sufficient information should be included in the drawings to provide the geometric definition to facilitate the repair of any partof the hull structure
7) normal storage location means a standard location where each SCF information item should be stored. However, those itemslisted as being on board in the table above should be on board as a minimum to ensure that they are transferred with theship on a change of owner
8) shore archive shall be operated in accordance with applicable international standards.
---e-n-d---o-f---n-o-t-e---
4.3 Review of ship construction file
4.3.1 The SCF shall be reviewed, at the time of new building, in accordance with the requirements ofparagraph 4.2 and the normal storage location shall be distinguished.
Guidance note:Review means the examination of the SCF that is carried out by the surveyor, at the end of the newbuilding process, in order toconfirm that:
— drawings and documents required under the paragraph 3 of the appendix 2 to the UR Z23, plus
— the possible additional drawings/documents provided by the shipyard, as per the ship constructional file (SCF) list of drawings/documents
are present in the copies of the SCF stored on board and in the ashore archive.The review shall not be intended as an assessment of the drawings/documents in order to verify their compliances with theapplicable rules/regulations.
---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---
4.3.2 For the SCF stored on board ship, the surveyor shall verify that the information is placed on board theship, upon completion of ship construction.
4.3.3 For the SCF stored on shore archive, the surveyor shall verify that the information is stored on shorearchive by examining the list of information included on shore archive, upon completion of ship construction.
5 Determination of number of surveyor(s)
5.1 General
5.1.1 The Society will assign adequate number of suitable qualified surveyor(s) for new building projectsaccording to the construction progress of each ship to meet appropriate coverage of the examination andtesting activities as agreed in the survey plan.
Part 2 Chapter 4 Section 9
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 122Fabrication and testing
DNV GL AS
CHANGES – HISTORIC
July 2019 edition
Changes July 2019, entering into force 1 January 2020Topic Reference Description
Welding workshop approval(WWA)
Sec.1 [1.3.3] andSec.1 Table 1
Added text to waive the WWA for builders fabricating alsoclass I and II pipes and removed components covered by theSociety's own fabrication / builder review.
Application of non-typeapproved welding consumables
Sec.1 Table 5 Added requirements for welding consumables without typeapproval.
Sec.1 Table 4 Clarification and added qualification to certificate.Welder qualification as perAWS
— 'T-butt' corrected to 'T-, K-, and Y-joints'— Wide gap welding: 'butt joints' corrected to 'butt joints and
T-, K-, and Y-joints', and added 'abutting member'.
Friction stir welding ofaluminium
Sec.5 [1.6.2] New subsection on friction stir welding of aluminium.
Essential fillet welds:clarification
Sec.5 [2.2.3] Essential fillet welds removed. Text rephrased to make itapplicable for welds (butt and fillet) in general. Removedwelding of highly stressed butt welds and cruciform jointslocated at large hatch openings because it is covered by weldsin hull structure.
Macro test from stop-restartposition
Sec.5 [3.6.2] Added single run manual and semi-automatic welding.
WPQT for pipe fillet joints:fracture test
Sec.5 [3.6.2] Added for pipe fillet welds: one additional macrosection test.
Bend test evaluation/acceptance criteria
Sec.5 [5.2.1] Specified requirements for corner cracks and added guidancenote for the evaluation of multiple small discontinuities.
Part 2 Chapter 4 Changes – historic
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 123Fabrication and testing
DNV GL AS
Topic Reference Description
WPS details for welding whereCTOD properties are required
Sec.5 [6.2.2] e) Requirement added that specific parameters affecting theCTOD properties shall be specified on the WPS. Guidance noteadded that the specification for chemical composition of basematerials may typically give ranges as indicated in EN 10225Option 18 or API RP2Z.
Welding procedurequalification range for TMmaterials
Sec.5 [6.2.2] a) The requalification requirement 'for change in delivery conditionTM to other', is removed.
Base material approval rangefor WPS
Sec.5 [6.2.2] b) Clarification by adding one more example, qualification of gradeE420 will qualify grades A420 to E420 and A40 to E40.
WPS / WPQT Maximumthickness qualified
Removed the 150 mm limit.
WPS / WPQT Thicknessapproval range for CTOD
A new subnote added for qualified thickness range in case ofCTOD requirement.
WPS / WPQT Thicknessapproval range for fillet weldsfor forging or casting androlled steel
A new subnote added as follows: 'for fillet welds on castingsand forgings, qualification of thickness ≥ 30 mm will qualifyunlimited maximum thickness'.
WPS / WPQT thicknessapproval range for single runhigh heat input welding
Sec.5 Table 8
Old note 2) (new note 7)) moved to the single run column andthickness range 12 < t ≤ 100.
Change of welding consumablebrand for high heat inputwelding
Sec.5 [6.2.6] Added: '- change of consumable brand for high heat inputwelding (> 50 kJ/cm)'.
Sec.5 [7] Text corrected such that impact toughness test at 1/2 t is onlyrequired for VL D/E47 with BCA, COD or BCACOD and thicknesst > 50 mm.
Temporary corrosion/oxidationpreventing coatings onsurfaces to be welded
Sec.6 [3.1] and Sec.6[5.3.5]
Text aligned and included temporary corrosion/oxidationpreventive coatings.
Cold forming of extra highstrength steels
Sec.6 [5.2.2] Added requirements and guidance for cold forming of extra highstrength steels up to VL 960.
Cold forming Sec.6 [5.2.3] Limitation of cold forming to grades up to VL 690.
Welding in cold formed areas Sec.6 [5.2.5] Clarified that special consideration is applicable for welding incold formed areas with cold forming more than specified limitgiven in Sec.6 [5.2.2].
Extension of NDT for non-conforming weldments
Sec.7 [5.2.1] Additional sub-item included to waive extended testing scope ifthe discontinuity is isolated and volumetric.
Inspection on tested weld Sec.8 [2.4.4.4] Text aligned to comply with IACS UR S14, Rev.6.
Clarification of requirementsto hydrostatic pressure test fordoors and hatch covers
Sec.8 Table 2 Doors and hatch covers which become immersed by anequilibrium or an intermediate water plane in a damagedcondition shall be subjected to a hydrostatic pressure test.
Part 2 Chapter 4 Changes – historic
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 124Fabrication and testing
DNV GL AS
July 2018 edition
Amendments February 2019Topic Reference Description
Sec.1 [1.3.2] Removed requirement for welding workshop approval of hull,superstructure taking part in the overall strength includingblocks.
Sec.1 [1.3.3] Clarified that WWA is not required for builders and theirsubcontractors for hull structures and approved manufacturer(AoM) qualified for welding.
Sec.1 Table 1 Removed WWA requirement for personnel lifts and pressureequipment.
Sec.1 Table 4 Removed hull structures and pressure equipment. Clarified thatWWA is not required for builders and their subcontractors forhull structure and repairs or alterations to fleet in service.
Sec.1 Table 7 Removed WWA requirement.
Sec.2 [1.2] Removed certification requirement.
Sec.2 Table 1 Removed WWA requirement.
WWA requirement for builders
Sec.5 [6.1.1] Removed WWA requirement.
Changes July 2018, entering into force as from date of publicationTopic Reference Description
Sec.3 Relevant rule text is reversed to January 2017 edition.Requirements according to IACS UR W32 removed.
Revision of rule text
Sec.3 [2.1.1] Added guidance note for IACS UR W32 as a recognisedqualification scheme for welders of hull structural steels.
Changes July 2018, entering into force 1 January 2019Topic Reference Description
NDT procedures to beapproved Sec.1 Table 6
Added for H135 in the column "Additional description":Applicable for vessel specific NDT procedure not alreadyapproved".
Text corrected for branchconnection, fillet weld fracturetest and include partialpenetration welds
Sec.5 [3.5.1], Sec.5[3.6.2], Sec.5 [6.2.3]
For branch connection "plate" is corrected to "pipe". Alternativetesting on specimens from a butt weld assembly is added. Textamended such that fracture test is only required for plate filletwelds. Partial penetration welds added to the definition for thequalified thickness range.
Part 2 Chapter 4 Changes – historic
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 125Fabrication and testing
DNV GL AS
Topic Reference Description
Charpy V-notch testrequirements for multi-passincreased toughness weldsaccording to Pt.5 Ch.2 Sec.10[2.2.5]
Sec.5 [5.4.1]
A design option for ULCV acc. to Pt.5 Ch.2 Sec.10 [2.2.5]requires multi-pass welds with increased toughness. For highstrength structural steels requirements added: the Charpy V-notch test temperature and the average value for absorbedenergy shall be the same as required for the base metal. Addednotch positions to be tested.
WPS for qualification of CTOD:validity scope for chemicalcomposition
Sec.5 [6.2.2]Requirement added: For steels for container ships wherequalification of CTOD for the weld is required, the chemicalcomposition limitations shall be agreed.
Move guidance note Sec.6 [5.1.3] Guidance note moved from Sec.6 [5.1.4] to Sec.6 [5.1.3].
Oxidation when welding onstainless steel Sec.6 [5.3.14]
Added a new paragraph for the shielding/backing gas ofstainless steel welds and a guidance note to avoid detrimentaloxidation.
Adjusted text for WPS/WPQTon BCA, COD and BCACODsteels
Sec.6 [5.3.20] Rephrasing of bullet 5.
Amend text for 'qualifiedinspection body' Sec.7 [1.1.1], [1.1.3] Deleted [1.1.3], amended Sec.7 [1.1.1] and guidance note
moved to Sec.7 [1.1.1].
Replaced indication byimperfection
Sec.7 [2.4.3] andSec.7 Table 3 Indication replaced by imperfection.
Moving NDT requirementfor upper hull longitudinalstructural members ofcontainer ships
Sec.7 [4.1.4], Sec.7Table 2 and Sec.7Table 3
Requirements transferred from Pt.5 Ch.2 Sec.10.
NDT requirements for weldson very thick steel plates forULCV according to Pt.5 Ch.2Sec.10 [2.2.5]
Sec.7 [4], Sec.7 [5]NDT procedures aligned with the usual DNV GL procedures.Introduction of the term "increased sensitivity NDT" which ismore accurate than previously used "enhanced NDT".
Simplify table for NDTacceptance criteria Sec.7 Table 3 Merged columns with same NDT acceptance criteria.
Text adjusted for non-conforming weldments Sec.7 [5.2.1] Adjusted the text for the scope of extended testing for non-
conforming discontinuity.
January 2018 edition
Amendments January 2018Only editorial corrections have been made.
Part 2 Chapter 4 Changes – historic
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 126Fabrication and testing
DNV GL AS
Changes January 2018, entering into force as from date ofpublication
Topic Reference Description
Sec.1 Table 6,Sec.1 Table 7,
Sec.1 Table 8
NDT procedures to be changed from agreed to approved. Newdocumentation type 'H135 - Non-destructive testing (NDT)procedure' added.
NDT procedures to beapproved
Sec.7 [2.1.1] NDT procedures to be changed from agreed to approved.
Welding procedurerequirements for highmanganese grades
Sec.5 [1.1.1],
Sec.5 [3.2.5],
Sec.5 [3.2.9],
Sec.5 [5.4.2],
Sec.5 [6.2.2],
Sec.5 [9.2.2],
Sec.5 [9.4.2],
Sec.5 [11]
Adjusted wording from austenitic stainless steel to austeniticsteel to include high manganese grades. Requirements for bendtesting aligned.
Wording with respect to CTODtest of BM
Sec.5 [3.2.10] Clarification that fracture mechanics (FM) testing for basematerial can be waived for specific cases.
Number and location ofhardness measurements forfillet weld
Sec.5 [3.6.1] andSec.5 [3.6.2]
Definition of stop/restart position for single run fillet weld.Hardness measurement for one macrosection taken from theweld start of the test assembly only.
WPQT Heat input rangecoverage for high heat inputwelding
Sec.5 [6.2.9] Qualified range for high heat input welding changed to+10/-25%.
WPQT Notch bar impact testfor austenitic stainless steelsfor liquefied gas systems
Sec.5 [9.2.2] Requirement concerning number of notch bar impact testspecimen for austenitic stainless steels aligned with IGC code.
Wide gap welding Sec.6 [5.3.3] Reduced application range of wide gap WPS in generalproduction welding in order to reduce possible weldimperfections.
Clarification of requirementsfor charpy v-notch testing
Sec.5 [8.2.2] — Deleted redundant statement on requirements for charpy v-notch test, covered by Sec.5 [5.4.1].
— Clarified that for WPQ test of COD grades - welds in plates,additional notch locations to be tested is applicable for t >50 mm.
July 2017 edition
Part 2 Chapter 4 Changes – historic
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 127Fabrication and testing
DNV GL AS
Changes July 2017, entering into force 1 January 2018Topic Reference Description
Sec.3 [1.1] New paragraphs inserted and previous paragraph relocated.
Sec.3 [2] New subsection added for 'Welders qualification for hullstructures'
Sec.3 [3] New subsection added for 'Welders qualification for otherapplications than hull structures'.
Implementation IACS UR W32 -
Qualification scheme forwelders of hull
structural steels
Sec.3 [4]Relocated subsection 1.5 for 'Requirements for weldingoperators'. Considered operators responsibility and adjustedthe required records of proficiency.
Hardness requirement is given for cases where norequirements are specified for base material and weldingconsumable.
Requirements to insert plates Sec.5 [1.5.1] Gap more than 1,5xt (or 25 mm) shall, unless speciallyagreed, be repaired by insert.
Add welding procedurerequirement for high heat inputwelding when consumablebrand change
Sec.5 [6.2.9]Added sentence in line with IACS UR W28, stating thatchange of consumable brand for processes with heat inputmore than 50 kJ/cm requires new qualification.
Added reference to CG-0051for NDT operator qualification Sec.7 [3.2]
Operators only producing radiographs and not performingfilm interpretation may be qualified and certified in RTat level 1 in accordance with an accredited 3rd partycertification scheme based on EN ISO 9712.
Visual testing -
qualification requirements
Sec.7 [1.4]
Sec.7 Table 1
Sec.7 [3]
Allow VT inspections by qualified personnel. Level II is notrequired for VT inspection.
Implementation of UR S14,rev.6 - Testing procedures ofwatertight compartments
Sec.8
In the last revision of UR S14 (Rev.6), it has been divided intwo parts, Part A for SOLAS-ships and Part B for non-SOLASships. Our rules are aligned with the new format.
There are changes to all sub-sections in section 8. S14 hasbeen used as the leading document and the rules have beenadopted as far as practicable.
Requirements to review of shipconstruction file (IACS UR Z23rev.6)
Sec.9 [4.3] New requirement implemented for review of ship constructionfile in accordance with IACS URZ23 Rev.6 in 4.3.
January 2017 edition
Main changes January 2017, entering into force 1 January 2017
• Sec.1 General— Sec.1 [1.3.1]: Reference to assignment of class has been deleted
Part 2 Chapter 4 Changes – historic
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 128Fabrication and testing
DNV GL AS
— Sec.1 [1.3.2]: Paragraph deleted— Sec.1 [1.3.3]: Applicable structures/components or WWA included— Sec.1 Table 2: Added reference for ISO 17662— Sec.1 Table 3: Reference to EN 1011-1 regarding thermal efficiency— Sec.1 Table 3: Heat input for multi-wire welding included— Sec.1 Table 3: Essential welding parameters included— Sec.1 Table 4: Clarification of applicability of WWA— Sec.1 Table 6: Additional description revised for welding— Sec.1 Table 7: Document type revised— Sec.1 Table 7: Additional description revised
• Sec.3 Qualification of welders— Sec.3 [2.1.1]: Reference to EN 287 deleted
• Sec.4 Welding consumables— Sec.4 [1.5.1]: Added steel groups— Sec.4 [1.5.4]: Added paragraph and reference for welding consumables for the repair of copper alloys— Sec.4 [1.5.5]: Added paragraph for welding consumables for other non-ferritic materials— Sec.4 [1.5.6]: Welding consumables for steel grades with minimum specified yield strength 890 and 960MPa included
• Sec.5 Welding procedures— Sec.5 [1.1.1]: BCA and COD grades included— Sec.5 [1.4.1]: Requirement for weldability of the base metal using high heat input welding deleted— Sec.5 [1.5.1]: Maximum thickness set for wide gap welding— Sec.5 [2.1.3]: Added Guidance Note for Calibration and validation— Sec.5 [2.1.6]: Weld bead included to weld parameters to be recorded— Sec.5 [2.1.7]: Added WPQR and corresponding— Sec.5 [3.1.1]: Guidance note revised— Sec.5 [3.1.2]: Paragraph transferred into guidance note— Sec.5 [3.2.5]: Mandrel diameter for SMYS > 690 MPa included— Sec.5 [3.6.1]: Added text for vertical-down fillet welds on structural steel grades A to F40— Sec.5 [5.3.2]: Maximum hardness limit for VL 890 and VL 960 included— Sec.5 [5.6.1]: Added text and guidance note / example for the qualification range of steels— Sec.5 [6.2.2]: Deleted under d) first bullet point; new qualification only for TM steels not pre-qualifiedrequested
— Sec.5 [6.2.6]: Information on consumable classification added— Sec.5 [6.2.9]: Added exemption for SMAW in welding current change from A.C. to D.C.— Sec.5 [8.2.3]: Added text in guidance note for essential parameters— Sec.5 [8.3.2]: Added definition for t— Sec.5 [9.2.2]: Adjusted text for Charpy V-notch locations acc. to the IGC code and added testtemperature for austenitic stainless steels
— Sec.5 [11.2.1]: Added minimum— Sec.5 [12.2.5]: Added paragraph for the macrosection— Sec.5 Table 15: Filler grade 5556 included
Part 2 Chapter 4 Changes – historic
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 129Fabrication and testing
DNV GL AS
• Sec.6 Fabrication and tolerances— Sec.6 [5.2.3]: Added text and guidance note for representatively cold formed material— Sec.6 [5.3.10]: Added text for tack welding - when integrated in production weld— Sec.6 [6.1.2]: Added or and followed by
• Sec.7 Non destructive testing of welds— Sec.7 [1.1.3]: Adjusted text for the inspection body to a guidance note
July 2016 edition
Main changes July 2016, entering into force January 2017
• Sec.1 General— Sec.1 Table 5: Document type H133 shall always be submitted— Sec.1 Table 5: Document type H150 removed and replaced by H200— Sec.1 Table 5: Document type Q010 and Q020 removed— Sec.1 Table 5: Document type H140 added to table— Sec.1 Table 5: Explanation for WPS added— Sec.1 Table 6: Document type Q010 and Q020 added— Sec.1 Table 6: Requirements for NDT procedures already given in the text are now added to the overviewtable.
• Sec.5 Welding procedures— Sec.5 [7.1.4]: Charpy V-notch test requirements have been aligned with IACS UR W31— Sec.5 [9.1]: Wording updated— Sec.5 [14]: Figure 28 removed
• Sec.6 Fabrication and tolerances— Sec.6 [5.3.3]: Wording updated
• Sec.7 Non destructive testing of welds— Sec.7 [2.4.1]: Wording updated
October 2015 editionThis is a new document.The rules enter into force 1 January 2016.
Amendments January 2016
• General— Only editorial corrections have been made.
Part 2 Chapter 4 Changes – historic
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 130Fabrication and testing
DNV GL AS
Amendments October 2015
• Sec.5 Welding procedures— Table 8 has been corrected.
Part 2 Chapter 4 Changes – historic
Rules for classification: Ships — DNVGL-RU-SHIP Pt.2 Ch.4. Edition July 2020, amended January 2021 Page 131Fabrication and testing
DNV GL AS
About DNV GLDNV GL is a global quality assurance and risk management company. Driven by our purpose ofsafeguarding life, property and the environment, we enable our customers to advance the safetyand sustainability of their business. We provide classification, technical assurance, software andindependent expert advisory services to the maritime, oil & gas, power and renewables industries.We also provide certification, supply chain and data management services to customers across awide range of industries. Operating in more than 100 countries, our experts are dedicated to helpingcustomers make the world safer, smarter and greener.
