32-SAMSS-004 DATED JAN 15-2012

Previous Issue: 13 December 2011 Next Planned Update: 23 February 2016

Revised paragraphs are indicated in the right margin Page 1 of 54

Primary contact: Naffaa, Mahmoud Youniss on 966-3-8809614

Copyright©Saudi Aramco 2012. All rights reserved.

Materials System Specification

32-SAMSS-004 15 January 2012

Manufacture of Pressure Vessels

Document Responsibility: Vessels Standards Committee

Saudi Aramco DeskTop Standards

Table of Contents

1 Scope............................................................ 2

2 Conflicts and Deviations................................ 3

3 References.................................................... 3

4 Definitions...................................................... 6

5 Responsibilities............................................. 8

6 Proposals...................................................... 8

7 Mechanical Design........................................ 8

8 Nozzles and Manways................................ 16

9 Internals....................................................... 19

10 Vessel Support............................................ 20

11 Clips and Attachments................................ 23

12 Materials...................................................... 24

13 Fabrication................................................... 30

14 Nondestructive Examination........................ 37

15 Postweld Heat Treatment............................ 42

16 Examination, Inspection, Pressure Tests and Repairs................ 43

17 Nameplates and Stampings........................ 47

18 Coatings and Painting................................. 48

19 Shipping Requirements............................... 48

20 Drawings, Calculations and Data................ 52

Table 1 – Nondestructive Examination Requirements…………………..………. 54

Document Responsibility: Vessels Standards Committee 32-SAMSS-004

Issue Date: 15 January 2011

Next Planned Update: 23 February 2016 Manufacture of Pressure Vessels

Page 2 of 54

1 Scope

1.1 This specification covers the minimum mandatory requirements for the

manufacture of pressure vessels (referred to hereinafter also as vessels).

The requirements are in addition to and supplement the requirements of the

ASME Boiler and Pressure Vessel Codes.

1.2 Vessels under the scope of this specification are purchased on a stand-alone

basis or as an integral part of a skid-mounted packaged equipment unit.

Note: This is applicable irrespective of the party responsible for placing the relevant purchase order (Saudi Aramco facility, LSTK contractor, sub-contractor, etc.).

1.3 This specification does not cover the following:

1) “UM” stamped pressure vessels per ASME SEC VIII D1.

2) In-service pressure vessels.

3) Devices used as an integral part of piping systems, made of what are

recognized as piping components (piping, fittings, etc.) and serve purposes

such as straining, filtering, mixing, separating, distributing, metering and

controlling flow.

4) Pressure vessels used as part of heating, ventilation and air conditioning

(HVAC) systems.

5) Compressed gas cylinders.

1.4 Pressure vessels under scope of this specification, having partial or complete

cladding, shall also conform to 32-SAMSS-031 in addition to the requirements

of this specification.

1.5 Low alloy steels for vessels intended for services within the scope of

API RP 934-A, API RP 934-C or API RP 934-E, shall meet all requirements of

the respective document of the aforementioned documents and this specification.

1.6 1 Cr- ½ Mo and 1 ¼ Cr- ½ Mo steels used for vessels not in hydrogen service

with design temperature below 440°C, shall meet all requirements of

API RP 934-C and this specification.

1.7 Where a requirement of a licensor’s or a relevant industry standard/specification

is more stringent than that of this specification, the most stringent requirement

will govern.

1.8 A vessel that is an integral part of a skid-mounted packaged equipment unit shall

be designed and manufactured by a manufacturer of such unit per the relevant

SAP database.

http://standards/docs/SAMSS/PDF/32-SAMSS-031.PDF




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2 Conflicts and Deviations

2.1 Any conflicts between this Specification and other applicable Saudi Aramco

Materials System Specifications (SAMSSs), Standard Drawings (SASDs), or

industry standards, codes, and forms shall be in writing by the Company or

Buyer Representative through the Manager, Consulting Services Department of

Saudi Aramco, Dhahran.

2.2 Direct all requests to deviate from this specification in writing to the Company or

Buyer Representative, who shall follow internal company procedure SAEP-302

and forward such requests to the Manager, Consulting Services Department of

Saudi Aramco, Dhahran.

3 References

Materials or equipment supplied to this specification shall comply with the latest edition

of the references listed below, unless otherwise noted.

3.1 Saudi Aramco References

Saudi Aramco Engineering Procedures

SAEP-302 Instructions for Obtaining a Waiver of a Mandatory

Saudi Aramco Engineering Requirement

SAEP-347 Supplying Material from Stockists

Saudi Aramco Materials System Specifications

01-SAMSS-016 Qualification of Storage Tanks and Pressured

Equipment for Resistance to Hydrogen-Induced

Cracking

32-SAMSS-020 Manufacture of Trays and Packing

32-SAMSS-031 Manufacture of Clad Vessels and Heat Exchangers

32-SAMSS-036 Manufacture of Small Pressure Vessels

Saudi Aramco Engineering Standards

SAES-A-007 Hydrostatic Testing Fluids and Lay-Up Procedures

SAES-A-112 Meteorological and Seismic Design Data

SAES-A-206 Positive Materials Identification

SAES-H-100 Coating Materials and Application

SAES-L-133 Corrosion Protection Requirements for Pipelines,

Piping and Process Equipment

http://standards/docs/SAEP/PDF/SAEP-302.PDF







http://standards/docs/SAES/PDF/SAES-A-007.PDF



http://standards/docs/SAES/PDF/SAES-H-100.PDF

http://standards/docs/SAES/PDF/SAES-L-133.PDF




Page 4 of 54

SAES-M-001 Structural Design Criteria for Non-Building

Structures

SAES-N-001 Industrial Insulation

SAES-W-010 Welding Requirements for Pressure Vessels

Saudi Aramco Standard Drawing

AA-036322 Anchor Bolt Details

Saudi Aramco Inspection Requirements

Form 175-321900 Manufacture of Pressure Vessels

Saudi Aramco Forms and Data Sheets

NMR-7919-1 Nonmaterial Requirements for Pressure Vessels

9527-ENG Pressure Vessel Data Sheet (herein referred to as

data sheet)

3.2 Industry Codes and Standards

American Institute of Steel Construction

AISC M011 Manual of Steel Construction

American Petroleum Institute

API RP 520 Part I - Sizing, Selection, and Installation of

Pressure Relieving Devices in Refineries

API RP 582 Recommended Practice and Supplementary Welding

Guidelines for the Chemical, Oil, and Gas

Industries

API RP 934-A Materials and Fabrication of 2 ¼Cr-1Mo, 2 ¼Cr-

1Mo-¼V, 3Cr-1Mo, and 3Cr-1Mo- ¼V Steel

Heavy Wall Pressure Vessels for High-

temperature, High-pressure Hydrogen Service

API RP 934-C Materials and Fabrication of 1 ¼ Cr-½ Mo Steel

Heavy Wall Pressure Vessels for High-pressure

Hydrogen Service Operating at or Below 825°F

(440°C)

API RP 934-E Materials and Fabrication of 1 ¼ Cr-½ Mo Steel

Pressure Vessels for Service above 825°F

(440°C)

http://standards/Docs/SAES/PDF/SAES-M-001.pdf

http://standards/docs/SAES/PDF/SAES-N-001.PDF

http://standards/docs/SAES/PDF/SAES-W-010.PDF

http://standards/docs/Standard_Drawings/PDF/AA-036322-001.PDF

http://standards/docs/Inspection_Requirements/PDF/175-321900.PDF

http://standards/docs/Nonmaterial_Requirements/PDF/SA-7919-1.PDF

http://standards/docs/Forms_Data_Sheets/PDF/SA-9527.PDF




Page 5 of 54

American Society of Civil Engineers

ASCE 7 Minimum Design Loads for Buildings and Other

Structures

American Society of Mechanical Engineers (Boiler and Pressure Vessel Codes)

ASME SA-20 Specification for General Requirements for Steel

Plates for pressure Vessels

ASME SA-388 Ultrasonic Examination of Heavy Steel Forgings

ASME SA-578 Specification for Straight-Beam Ultrasonic

Examination of Rolled Steel Plates for Special

Applications

ASME SEC V Nondestructive Examination

ASME SEC VIII D1 Rules for Construction of Pressure Vessels

ASME SEC VIII D2 Rules for Construction of Pressure Vessels,

Alternative Rules

ASME B16.5 Pipe Flanges and Flanged Fittings NPS ½ through

NPS 24

ASME B16.25 Butt-welding Ends

ASME B16.47 Large Diameter Steel Flanges NPS 26 through

NPS 60

ASME PCC-1 Guidelines for Pressure Boundary Bolted Flange

Joint Assembly

American Society for Testing and Materials

ASTM A380 Practice of Cleaning, Discleaning and Passivation

of Stainless Steel Part Equipment and System

ASTM E381 Standard Method of Macrotech Testing Steel Bars,

Billets, Blooms, and Forgings American Society

for Nondestructive Testing

American Society for Non-destructive Testing

ASNT CP-189 Standard for Qualification and Certification of

Nondestructive Testing Personnel

International Standards Organization

ISO 15156 Petroleum and Natural Gas Industries - Materials

for Use in H2S Containing Environments in Oil

and Gas Production




Page 6 of 54

National Association of Corrosion Engineers

NACE RP0472 Methods of Control to Prevent In-Service Cracking

of Carbon Steel Welds in P-1 Materials in

Corrosive Petrochemical Refining Environments

NACE RP0590 Recommended Practice for Prevention, Detection

and Correction of Deaerator Cracking

NACE TM0208 Laboratory Test to Evaluate the Vapor-Inhibiting

Ability of Volatile Corrosion Inhibitor Materials

for Temporary Protection of Ferrous Metal

Surfaces

Process Industry Practices

VEFV1100 Vessel/S&T Heat Exchanger Standard Details

Welding Research Council

WRC 107 Welding Research Council Bulletin

WRC 297 Welding Research Council Bulletin

4 Definitions

AARH: Average arithmetic roughness height, which is a measure of surface texture.

Cyclic Service: Services that require fatigue analysis according to screening criteria

per 5.5.2 of ASME SEC VIII D2. This applies to Division 1 and Division 2 of

ASME SEC VIII.

Design Engineer: The Engineering Company responsible for specifying on the data

sheet the mechanical design requirements for pressure vessels.

Design Thickness: Sum of thickness required to withstand all primary loads and an

allowance for corrosion.

High - Alloy Steels: Steels with a total alloying content more than 5%.

Hot Forming: Forming operations carried out at an elevated temperature such that re-

crystallization occurs simultaneously with deformation.

Hydrogen Induced Cracking (HIC) Environment: Process streams that introduce

HIC according to SAES-L-133.

Hydrogen Service: Process streams containing relatively pure hydrogen and process

streams containing hydrogen as a component with an absolute partial pressure of

350 kPa (50 psi) and higher.

http://standards/docs/Pip/PDF/VEFV1100.PDF





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Lethal Services: Process streams containing a concentration of hydrogen sulfide in

excess of 20% volume per total volume of vessel shall be considered as lethal service.

Other services as determined by the project design may also be designated as lethal

services.

Low - Alloy Steels: Steels with a total alloying content of less than 5% but more than

specified for carbon steels.

MDMT: Minimum design metal temperature determined by the Design Engineer and

specified in the data sheet.

Nominal Thickness: Thickness selected as commercially available, and supplied to the

Manufacturer. For plate material, the nominal thickness is the measured thickness of the

plate at the joint or location under consideration after forming.

Pressure Vessel and Vessel: As defined in the ASME Boiler and Pressure Vessel

Codes.

Saudi Aramco Buyer: The person or company authorized by Saudi Aramco to procure

pressure vessels to the requirements of this specification.

Saudi Aramco Engineer: The chairman of the Vessels Standards Committee.

Saudi Aramco Inspector: The person or company authorized by the Saudi Aramco

Inspection Department to inspect pressure vessels to the requirements of this

specification.

Skid-mounted packaged equipment unit: Self-contained units for process and utility

applications (e.g., air dryers, portable air compressors, filtering unit, nitrogen

generation, dehydration, etc.) fabricated and skid-mounted in one section. Such unit

consists of equipment (pressure vessels, compressors, pumps, storage tank, etc.),

interconnecting piping, electrical and/ or instrument components, and support

structures.

Sulfide Stress Cracking (SSC) Environment: Process streams that introduce SSC

according to SAES-L-133.

Thick Wall: Nominal thickness of a pressure-retaining vessel’s component (shell,

head, nozzle, etc.) greater than 50 mm.

Unfired Steam Drums: As defined in ASME SEC VIII D1, paragraph U-1 (g) (2).

Utility Services: Water, air and nitrogen services.

Vessel Manufacturer: The Company responsible for the manufacture of new pressure

vessels in accordance with this specification.





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5 Responsibilities

The Vessel Manufacturer is responsible for the manufacture of pressure vessels, which

includes complete mechanical design, Code and structural calculations, supply of all

materials, fabrication, nondestructive examination, inspection, testing, surface

preparation, and preparation for shipment in accordance with the completed data sheet

and the requirements of this specification.

6 Proposals

6.1 The Vessel Manufacturer's proposal shall be based on details for individual

vessels and the requirements of this specification.

6.2 The Vessel Manufacturer may offer an alternative design, but must quote on the

base inquiry documents.

6.3 The proposal shall include a detailed description of any exception to the

requirements of this specification.

7 Mechanical Design

7.1 General

7.1.1 All pressure vessels shall be designed in accordance with the rules of

the Boiler and Pressure Vessel Codes, ASME SEC VIII D1 or

ASME SEC VIII D2 (herein referred to as the Codes), and the

requirements of this specification.

7.1.2 The ASME SEC VIII D1 or ASME SEC VIII D2, to which a vessel is

to be manufactured, shall be in accordance with the data sheet.

7.1.3 Should the Vessel Manufacturer have any part of a stress analysis

executed by a third party, the Vessel Manufacturer shall advise the

Saudi Aramco Engineer.

7.1.4 No proof testing shall be permitted unless specifically approved by the

Saudi Aramco Engineer.

7.1.5 No credit shall be given to thickness of integrally-bonded or weld

metal overlay cladding in calculating material thickness, required to

sustain all primary loads.

7.1.6 Application of ASME Code Cases to the manufacturing of pressure

vessels requires approval of the Saudi Aramco Engineer.




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7.1.7 Unfired steam drums shall be manufactured and stamped in accordance

with the requirements of this specification.

7.1.8 All welded joints of category A, B, C and D shall be complete fusion

full penetration welds, except for joint welds of slip-on flanges

specified per paragraph 8.1.3(d) of this specification.

7.2 Design Pressure

The value of design pressure(s) shall be in accordance with the data sheet.

Commentary Note:

Design pressure is the maximum difference in pressure between the inside and the outside of a vessel, or between the chambers of a combination unit. The term internal design pressure is used when the internal pressure is greater than the external pressure. However, the term external design pressure is used when the internal pressure is less than the external pressure.

7.2.1 Unless otherwise specified on the data sheet the design pressure will be

assumed to be at the top of the vessel in the operating position.

7.2.2 Design pressure(s) acting at the bottom of vessels shall take into

account pressure heads, both static and dynamic, due to the maximum

liquid levels.

7.2.3 Design pressure differential for the partition(s) separating the

compartment(s) of multi-compartment vessels shall be as specified on

the data sheet.

7.2.4 The external design pressure and corresponding temperature shall be as

specified on the data sheet.

7.2.5 Requirements for the design of packing bed supports for vessels that

contains packing shall be as specified on the data sheet.

7.3 Maximum Allowable Working Pressure

7.3.1 The Vessel Manufacturer shall calculate the maximum allowable

working pressure (MAWP) acting on the top of a vessel, in the hot and

corroded condition in accordance with the applicable Code.

7.3.2 The MAWP of a vessel shall not be limited by flange ratings.

7.4 Design Temperature

7.4.1 The value of design temperature(s) shall be as specified on the data

sheet.




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7.4.2 Where there are differences in the design temperatures for different

zones in a vessel, the extremities of these zones will be shown on the

data sheet.

7.5 Minimum Design Metal Temperature (MDMT)

The value(s) of the minimum design metal temperature (MDMT) shall be as


7.6 Service and Description

7.6.1 The service of a vessel; hydrocarbon, hydrogen, caustic, amine, wet

sour, steam or utility and whether the service is cyclic and/or lethal

shall be as specified on the data sheet.

7.6.2 The process description of a vessel (for examples: Amine Regenerator,

Air Receiver) shall be specified on the data sheet.

7.7 Joint Efficiency

7.7.1 The joint efficiency shall be as specified on the data sheet.

7.7.2 A joint efficiency of 85% or higher shall be specified for the design of

all pressure containing components of ASME SEC VIII D1 pressure

vessels.

7.8 Corrosion Resistance

7.8.1 Corrosion allowance shall be as specified on the data sheet.

7.8.2 The corrosion allowances required for tray assemblies, except for

attachments welded to pressure boundary components and intended to

support internals, e.g., tray support rings, brackets, etc., shall be in

accordance with the requirements of 32-SAMSS-020.

7.8.3 Cladding shall be applied according to the boundaries as specified on

the data sheet.

7.9 Nominal Thickness

Nominal thickness of shells and heads shall not be less than the following:

a) Carbon steels, 6 mm.

b) Low chrome alloy steels, 5 mm.





Page 11 of 54

7.10 Head Types

7.10.1 Refer to the data Sheet for the type of head.

7.10.2 The type of heads to be used shall be ASME 2:1-ellipsoidal or ASME

hemispherical.

7.10.3 ASME flanged flat heads and ASME torispherical heads can be used only

for air and water services up to a design pressure of 690 kPa (100 psi).

7.10.4 One piece construction (made from one-piece or welded multi-piece

blanks) shall be used for heads with nominal thickness greater than

50 mm and vessels in cyclic, hydrogen or lethal services. Other types

of head construction shall require prior approval of Saudi Aramco

Engineer as defined in this specification.

Note: Following shall be submitted to support review of the proposed multi-segment construction head:

a) Layout of head.

b) Nondestructive examination.

c) Forming procedure and,

d) Heat treatment procedure, as applicable.

7.10.5 Heads in vessels with design thickness greater than 50 mm shall be

hemispherical unless 2:1 ellipsoidal heads are deemed more

economical.

7.10.6 Minimum inside radius of knuckles for conical transition sections or

torispherical heads shall be as follows:

a) Not be less than 15% of the outside diameter of the adjoining

cylindrical section with conical section of thickness more than

50 mm.

b) Not be less than 10% of the outside diameter of the adjoining

cylindrical section with conical section of transition sections or

torispherical heads with thickness more than 19 mm or less than

50 mm.

c) Not be less than 6% of the outside diameter of the adjoining

cylindrical section with conical section of transition sections or

torispherical heads with thickness 19 mm and less.

7.10.7 Reinforcing for conical transition sections in vessels with design

thickness greater than 50 mm shall be provided by increased plate




Page 12 of 54

thickness. Use of reinforcing rings is prohibited.

7.10.8 Shell-to-internal head joint shall be only any of the following details:

a) Forged junction ring according to ASME SEC VIII D2,

Table 4.2.5 - Detail 7.

b) Weld build-up construction connecting shell to internal head.

This is not applicable to vessels in cyclic service.

7.10.9 Joint details in paragraph 7.10.8 shall provide a smooth transition,

minimizing peak stress concentration effects. The inner radius of the

weld build-up and forged detail shall be minimum 1 inch. Backing

strips used in fabricating the junction shall be removed after

completion of welding. All welds shall be ground smooth flush

contour of the joined parts.

7.11 Loads

7.11.1 Wind and Earthquake Loads

a) The Vessel Manufacturer shall calculate the static effects of loads

due to wind and the effects due to earthquake loads acting on the

vessel in the operating position accordance with the requirements

of this specification.

b) Wind and seismic loads shall be calculated for the vessel in its

erected position in accordance with ASCE 7, using Occupancy

Category IV and based on design data corresponding to the site

location per SAES-A-112.

c) Wind pressures shall be assumed to act on the projected surface

area of the pressure vessel and shall include due allowances for

platforms, ladders, piping, insulation, and equipment supported

from the pressure vessel as specified on the data sheet.

d) Seismic loads shall include due allowances for platforms, ladders,

piping, insulation, and equipment supported from the pressure

vessel as specified on the data sheet.

e) The maximum allowable deflection in the corroded condition at

the top tangent line of a vessel shall not exceed 150 mm / 30 m of

height.

7.11.2 Wind-induced Vibration

1) Vertical vessels shall be checked for wind-induced vibration by





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the Vessel Manufacturer for the following cases:

a) H > 30 m with H/D ratio > 15

b) W/HD² < 400

Where:

H is the height of the vessel in meters, including the

supports.

D is the diameter of vessel in meters.

(For multi-diameter vessels the diameter shall equal the

weighted diameter of the top third).

W is the weight of the vessel in kilograms in both the

erected empty and operating conditions.

2) The use of vortex breakers or guying devices in order to maintain

stresses, due to wind-induced vibration within allowable limits, is

prohibited.

3) The fatigue life of those vessels susceptible to wind induced

vibration shall be a minimum of one million cycles. The fatigue

curves in ASME SEC VIII D2 shall be used for the materials at

the specified design temperature.

7.11.3 Dead Weights of a Vessel

Design of vessels shall consider the following dead loads:

a) Weight of vessel including internals, supports (e.g., skirts, lugs,

saddles and legs), and appurtenances (e.g., platforms, ladders,

etc.).

b) Weight of vessel contents under operating and testing conditions.

c) Weight of refractory linings, insulation.

d) Weight of attached equipment such as motors machinery, valves,

other vessels, and piping.

7.11.4 Piping, Equipment and External Loads

a) The Vessel Manufacturer shall ensure that local stresses imposed

on a vessel due to piping (other than the dead load), equipment,

lifting, supports and other external loads do not exceed the

allowable limits in accordance with the applicable Code.




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b) Refer to the data sheet for piping and equipment loads imposed

on a vessel.

7.11.5 Dynamic Loads

Dynamic loads caused by the action of vibratory equipment (e.g.,

agitators), liquid sloshing, sub-liquid surface jets, etc.

7.11.6 Thermal Loads

Thermal Loads are loads caused by thermal transients and restraining

thermal expansion/ interaction of the vessel and/ or its support(s).

7.12 Load Combinations

7.12.1 All components of a vessel, including its support(s), shall be designed

to withstand stresses resulting from load combinations in accordance

with, but not be limited to, those shown in Table 4.1.2 of

ASME SEC VIII D2.

7.12.2 Anchor bolts shall be designed for load combinations, based on the

allowable stress design method (Service Loads) in accordance with

SAES-M-001.

7.12.3 All pressure vessel components whether shop or field fabricated shall

be designed to withstand a full hydrostatic test in the erected position.

7.12.4 Combined stresses due to full hydrostatic test and the greater of wind

and earthquake loads shall be within the allowable limits per

ASME SEC VIII D2, paragraph 4.1.6.2, based on the lowest Specified

Minimum Yield Strength (SMYS) of the materials of construction at

test temperature. However, wind and earthquake design loads can be

reduced to 50% of its values.

7.12.5 Loads (moments or forces) acting on a vessel due to external piping

that will affect the overall integrity of the vessel shall be added to

moments and forces due to other external primary loads (weight, wind

or earthquake loads). Addition of piping loads shall be based on

performing stress analysis.

7.13 Stress Analysis

7.13.1 Where applicable, the requirements for thermal stress and fatigue stress

analyses shall be as specified in the data sheet. Analysis methods and

stress combination limits presented in Division 2, Section 5, shall be

used for vessels under scope of Division 1 and Division 2. However,

http://standards/Docs/SAES/PDF/SAES-M-001.pdf




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allowable stresses shall be taken from the respective tables of

ASME SEC II for each division for the corresponding material and

temperature.

7.13.2 The Design Engineer is responsible for specifying the heat transfer

coefficients to be used for all thermal stress analysis.

7.13.3 Thermal Analysis

1) A thermal stress analysis is required for a vessel, if a thermal

gradient (calculated under steady state operating conditions and,

if applicable, transient operating conditions) across any vessel

section exceeds 65°C (150°F), in a distance equal to the square

root of R times T, where:

- R is the radius of the vessel component under consideration and,

- T is the thickness of the component under consideration

- R and T have the same units.

2) As a minimum, the scope of the stress analysis shall include the

following junctures, as applicable:

- Head-to-shell

- Support-to-vessel

- Nozzle-to-shell, considering external piping loads

- Tray supports to vessel wall

3) Thermal analysis shall be based on gradients under steady state

design conditions and also, if applicable, transient design

conditions.

4) Thermal gradients may be reduced to within allowable limits

with the provision of:

a) Thermal sleeves in pressure-retaining components

b) Hot-box design at the skirt-to-vessel junction in skirt-

supported vessels with design temperatures greater than

260°C (500°F).

7.13.4 Fatigue Analysis

1) Scope of the required stress analysis shall be as specified in the

data sheet, in accordance with the rules of Division 2, by the

Design Engineer.




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2) As a minimum, the scope of the stress analysis shall include the

following junctures, as applicable:

- Head-to-shell

- Support-to-vessel

- Nozzle-to-shell, considering external piping loads

- Tray supports to vessel wall

3) Analysis shall be based on the calculated number of cycles for a

minimum 20 year service life, as determined in accordance with

the rules of Division 2, paragraph 5.5.2.

4) The number of cycles shall include the number of start-ups, shut-

downs, emergency shut-downs, and upset conditions.

7.13.5 Local Stress Analysis

Stress analysis due to piping, equipment, lifting, supports and other

external loads shall be completed in accordance with the procedures as

detailed in WRC 107, WRC 297 or a finite element analysis.

8 Nozzles and Manways

8.1 General

8.1.1 The quantities, sizes, ratings, (ASME pressure classes), facings,

elevations, and orientations of nozzles and manways shall be as


8.1.2 Unless otherwise specified on the data sheet, the minimum projections

for nozzles and manway necks, as measured from the outside surface

of the shell or head to the face of a flange, shall meet the following

requirements:

a) 6 inches for NPS 6 nozzles and smaller.

b) 8 inches for NPS 8 nozzles and larger and manways necks.

c) For insulated vessels, projection shall be sufficient to allow

bolting of studs without interference with the insulation.

d) For vessel drain connections and other connections, where a

process stream is likely to be stagnant, the projection shall not

exceed three times the connection nominal diameter.




Page 17 of 54

8.1.3 Permissible types of flanges for nozzles and manways are according to

the following:

a) Forged steel long welding neck flange.

b) Forged steel welding neck flange. Such type of flange is welded

to seamless pipe, rolled plate with 100% radiography or an

integrally reinforced contour shaped forged nozzle or manway.

The bore of flange shall match the bore of nozzle and manway, as

applicable.

c) Studded nozzles and proprietary designs may be offered as

alternatives provided their design is in accordance with the

applicable Code and approved by the Saudi Aramco Engineer.

d) Slip-on type flange with seamless pipe nozzle necks or rolled

plate with 100% radiography is permissible for vessels, which are

integral parts of skid-mounted packaged equipment units, in only

non-cyclic air and water services with design temperature and

design pressure not exceeding 121C (250F) and 1.7 MPA (245

psi), respectively. Slip-on flange shall be welded on the front or

face and at the back of the hub.

8.1.4 A body flange shall be constructed of a single-piece forging.

8.1.5 Nozzles less than 2-inch NPS are not permissible.

8.1.6 Only flanged nozzles shall be used.

8.1.7 Vessels in services other than air and water shall be provided with a

minimum 2-inch NPS flanged steam-out connection.

8.1.8 The ends of butt-welded connections shall be in accordance with

ASME B16.25.

8.1.9 The Vessel Manufacturer shall design nozzles that are required for the

supporting of mechanical mixers and shall include the additional loads

and dimensional tolerances as specified on the data sheet.

8.1.10 Minimum four gusset plates for the reinforcement of nozzles

supporting mixers shall be provided.

8.1.11 Minimum inside corner radius of integrally reinforced contour nozzles

and manways shall be 13 mm.

8.1.12 Design of flanged connections with stud bolts of diameter 1½ inch and

above shall be such as to provide clearance to permit use of a stud and




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bolt-tensioning device.

8.2 Reinforcement of Openings

8.2.1 Reinforcement of vessel openings shall be in accordance with the

applicable Code and this specification.

8.2.2 The thickness of reinforcing pads shall not exceed the shell or head

thickness of a vessel.

8.2.3 Use of internal reinforcing elements is not permitted.

8.3 Flange Ratings, (ASME Pressure Classes) and Facings

8.3.1 The ASME pressure classes and facings shall be as specified on the

data sheet.

8.3.2 Bolted joints specified with non-ASME flanges shall be designed to

meet all anticipated loading conditions of the vessel.

8.3.3 Pressure ratings for standard flanges shall be in accordance with the

following:

a) ASME B16.5 for flanges NPS 24 and smaller.

b) ASME B16.47, Series A for flanges larger than NPS 24.

8.3.4 Gasket seating surfaces shall comply with the following:

a) For spiral wound gaskets, 125 to 250 AARH, in all services,

except hydrogen.

b) For spiral wound gaskets in hydrogen service, 125 to 150 AARH.

c) The side-walls of rings joint flanges in all services, 63 AARH.

d) For Nonmetallic gaskets, 250 to 500 AARH.

8.3.5 Machined surfaces other than gasket contact faces shall not exceed

500 AARH.

8.4 Manways

8.4.1 The number, nominal inside diameter and locations of manways shall

be as specified in the data sheet.

8.4.2 All manways shall be circular. The manway covers shall be hinged or

provided with handling davits as specified on the data sheet, according

to PIP VEFV1100.





Page 19 of 54

8.5 Attachment Details for Nozzles, Manways and their Connections

8.5.1 All nozzles and manway necks shall be attached by welding completely

through the total thickness of the vessel shell, head or nozzle wall,

including any reinforcement. Backing rings used in attaching nozzles

and manways to vessels shall be removed after welding.

8.5.2 Permissible types of nozzles, manways and their connections shall be

according to the table below.

Design Conditions / Services Group Attachment

Figure Reference from Indicated ASME Code Section VIII

Division 1 Vessels Division 2 Vessels

Group I

a. Pressure-retaining vessel’s component (shell, head,

nozzle or manway) with design thickness greater than 50 mm

b. Unfired steam boilers with design pressure

exceeding 50 psi c. Lethal, hydrogen and cyclic services d. Openings larger than 900 mm (Note 1) e. Design temperature greater than 400°C (Note 1) f. Low alloy steel vessels with design thickness greater

than 25 mm (Note 1) g. Vessels that will undergo PWHT (Note 1)

All nozzle sizes and manway necks

Connections attached to nozzles and manways

Figure UW-16.1, details: (f-1), (f-2), (f-3) or (f-4)

Table 4.2.13, details: (1), (2), (3), (4), (5) or (6)

Group II Design conditions and service other than those in Group I of this table

NPS 4 and smaller nozzles

Figure UW-16.1, details: (a), (a-1), (b), (c), (d), (e), (f-1), (f-2), (f-3), (f-4) or (g).

- Table 4.2.10, details: (1), (2), (3), (4), (6), (7) or (9) - Table 4.2.11, detail (2) - Table 4.2.13, details: (1), (2), (3), (4), (5) or (6)

Nozzles larger than NPS 4 and manway necks Figure UW-16.1, details:

(c), (d), (e), (f-1), (f-2), (f-3), (f-4) or (g) Connections attached to

nozzles and manways

Note 1: Alternatively, detail per Figure UW-16.1(g) may be used for Division 1 vessels provided that design conditions/ services per a, b

and/or c of group I are not applicable.

8.5.3 Integrally reinforced contour shaped attachments made partially or

completely of weld build up are prohibited.

9 Internals

9.1 All fixed and removable internals, including trays, packing, distributors, screens,

etc. shall be specified on the data sheet.

9.2 Tray rings and tray supports that are welded to vessels shall be designed by the

tray manufacturer and supplied and installed by the Vessel Manufacturer in

accordance with the requirements of 32-SAMSS-020.





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9.3 The Vessel Manufacture shall design, supply and install all other internals,

except for trays, as specified on the data sheet.

9.4 All removable internals are to be designed so that they may be passed through

tray and vessel manways.

9.5 Internal ladder rungs shall be provided by the Vessel Manufacturer according to

PIP document VEFV1100.

10 Vessel Support

10.1 General

10.1.1 Refer to the data sheet for the type of support.

10.1.2 Supports shall be designed to prevent excessive localized stresses due

to deformations produced by the internal pressure, primary loads and,

if applicable, thermal gradients in the vessel and support system.

10.1.3 Each vessel shall be designed as a self-supporting unit in accordance

with the requirements of the applicable Code and AISC.

10.1.4 All supports shall be continuously welded to the vessel.

10.1.5 The material of anchor bolts shall be in accordance with this

specification.

10.1.6 Base plates shall be designed by the Vessel Manufacturer for all

loading conditions in accordance with this specification.

10.1.7 The allowable concrete bearing stress to be used for the design of base

plates shall be 5170 kPa.

10.2 Supports for Vertical Vessels

10.2.1 The data sheet shall specify the type, location and overall dimensions

required for the design of supports for vertical vessels.

10.2.2 The Vessel Manufacturer shall design all supports required, including

skirts, legs, lugs, base plates, number of anchor bolts in accordance

with the data sheet.

10.2.3 Skirts shall have a minimum thickness of 6 mm.

10.2.4 The mean corroded diameter of the shell and the mean diameter of the

skirt shall coincide [rounded off to the nearest 3 mm], and shall be





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symmetrical about the vessel centerline. Exceeding this offset limit

shall require prior approval of the Saudi Aramco Engineer, as defined

in this specification, supported by stress analysis.

10.2.5 Hot-box design when specified for skirt-supported vessels with design

temperatures greater than 205°C (400°F) shall be in accordance with

PIP VEFV1100 and dimensions that meet the intent of reducing the

thermal gradient at the skirt-to-vessel junction.

10.2.6 One minimum 500 mm diameter skirt access opening shall be provided

for vessels with diameters equal to and larger than 1200 mm.

For vessels with diameters less than 1200 mm, skirt access opening

diameter shall be minimum one half of the vessel diameter.

Skirt access opening diameters smaller than the above specified shall

require prior approval of the Saudi Aramco Engineer. It is the vessel

manufacturer's responsibility to determine the need for reinforcing the

opening, according to the applicable Code.

10.2.7 Piping passing through skirt openings shall be adequately supported to

prevent damage during shipment.

10.2.8 The Vessel Manufacturer shall provide skirt bracing to prevent

buckling during shipping and lifting in the field.

10.2.9 Skirt-to-vessel juncture details for vessels with design thickness greater

than 50 mm and vessels in cyclic, hydrogen or lethal services shall be

only any of the following details:

a) Forged junction ring: according to ASME SEC VIII D2,

Figure 4.2.4(e).

b) Weld build-up construction (connecting skirt to head): according

to ASME SEC VIII D2, Figure 4.2.4(b). (Exception: This is not

applicable to vessels in cyclic service.)

c) Weld build-up construction (connecting skirt to shell): according

to ASME SEC VIII D2, Figure 4.2.4(f). (Exception: This is not

applicable to vessels in cyclic service.)

d) Forged skirt-to-shell junction ring: similar to ASME SEC VIII, D2,

Table 4.2.5 - Detail 7.

10.2.10 Joint details in paragraph 10.2.9 shall provide a smooth transition,

minimizing peak stress concentration effects. The inner radius of the

weld build-up and forged detail shall be minimum 1 inch.

Backing strips used in fabricating the junction shall be removed after





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completion of welding. All welds shall be ground smooth flush

contour of the joined parts.

10.2.11 Skirt-to-vessel juncture in vessels other those specified in paragraph

10.2.9 shall be according to ASME SEC VIII D2, Figure 4.2.4, detail

(a), (b) or (c) and shall meet the following weld spacing requirements:

1. Adjacent edges of the head-to-shell and skirt-to-head welds shall

not be closer than the head thickness or 1 inch, whichever is

greater.

2. Adjacent edges of the skirt-to-shell weld and any category B weld

joint shall not be closer than the shell thickness or 1 inch,

whichever is greater.

10.3 Supports for Horizontal Vessels

10.3.1 Two saddles with anchor bolts shall be used to support horizontal

pressure vessels. The vessel shall be fixed at one saddle support and

free to slide at the other saddle. Saddle base plates shall be in full

direct contact with the foundation.

10.3.2 The data sheet shall specify locations of the fixed and sliding saddles

and dimension from vessel centerline to underside of saddle base plate.

10.3.3 The shell shall be analyzed in accordance with the “LP Zick” method.

Saddle supports and the vessel shell shall be analyzed for operating and

hydrotest loads including any piping, wind or other external loads.

10.3.4 Minimum of 10 mm thick reinforcing pad is required at the junction of

the saddle and the vessel with all corners rounded to a minimum radius

of 50 mm.

10.3.5 The anchor bolt holes on the sliding-end saddle shall be slotted to

facilitate thermal expansion/ contraction along the longitudinal axis of

the vessel.

10.4 Anchor Bolts

10.4.1 The Vessel Manufacturer shall determine the size and number of

anchor bolts required.

10.4.2 Anchor bolts shall straddle vessel centerlines on the north-south, east-

west axes.

10.4.3 Anchor bolts shall not be less than 19 mm minimum nominal diameter.




Page 23 of 54

10.4.4 Design of anchor bolts shall be based on the following allowable stresses:

a) 104 MPa (tension).

b) 69 MPa (shear).

10.4.5 Vessels supported on skirts, lugs or legs shall be provided with an even

number of anchor bolts with a minimum of four anchor bolts.

10.4.6 Vessels supported on saddles shall be provided with an even number of

anchor bolts with a minimum of two anchor bolts per saddle.

11 Clips and Attachments

11.1 General

The Vessel Manufacturer shall supply and install all clips and attachments as


11.2 Insulation Supports

11.2.1 Support for insulation system shall be according to the data sheet.

11.2.2 The Vessel Manufacturer shall supply and install supports required for

insulation.

11.2.3 The bottom heads of vertical vessels that are externally insulated shall

be provided with 12 mm blank nuts. Blank nuts shall be welded on

edge and located on 300 mm square centers.

11.3 Refractory Supporting System

11.3.1 Anchoring system of refractory lining shall be according to the data

sheet.

11.3.2 The Vessel Manufacturer shall supply and install anchoring system

required for refractory.

11.4 Fireproofing Supports

11.4.1 Support for fireproofing system shall be according to the data sheet.

11.4.2 The Vessel Manufacturer shall supply and install supports required for

fireproofing materials.

11.4.3 Vertical vessels, which are not externally insulated, shall be provided

with a 5 mm thick steel weather cap on the skirt to provide a flashing




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for fireproofing.

11.5 Grounding Lugs

All pressure vessels shall be provided with a grounding lug connection welded

to the vessel support in accordance with PIP VEFV1100.

11.6 Equipment Davit

11.6.1 A davit for the lifting of equipment shall be supplied when specified on

the data sheet.

11.6.2 The davit shall be in accordance with PIP VEFV1100.

11.7 Reinforcing Pads

Reinforcing pads for all internal and external welded attachments shall be sized

to meet requirements of paragraph 7.11.4 of this specification. Pads shall be a

minimum of 10 mm (3/8") thick, but shall not exceed the shell thickness; with

all of their corners rounded to a minimum radius of 50 mm. Distance from any

edge of the attachment to the closest edge of the reinforcing pad shall not be less

than 50 mm.

12 Materials

12.1 General

12.1.1 All carbon, low alloy and high alloy steels required for pressure and

non-pressure components shall be as specified on the data sheet.

12.1.2 Prior approval by the Saudi Aramco Engineer is required for use of

alternative materials of construction for carbon and low alloy steels

pressure vessels. Alternative materials must comply with all the

requirements of the applicable Code and this specification.

12.1.3 Material specifications and tests procedures for base metal and

weldments materials for 1 Cr- ½ Mo, 1 ¼ Cr- ½ Mo, 2 ¼ Cr-1 Mo,

2 ¼ Cr-1 Mo- ¼ V, 3 Cr-1 Mo and 3 Cr-1 Mo- ¼ V shall be submitted

to Saudi Aramco Engineer for review and approval prior to ordering

the materials from the mill.

12.1.4 All materials must be clearly identified and provided with legible

original or certified true copies of Mill Test Certificates. Lack of

adequate identification and certification shall be cause for rejection.






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12.1.5 1 Cr- ½ Mo and 1 ¼ Cr- ½ Mo steels with thickness exceeding 100 mm

can be used for components (shell, head, integrally reinforced nozzles,

flanges, etc.) of vessels within scope of API RP 934-C, API RP 934-E

and paragraph 1.6 of this specification, provided that fracture toughness

requirements of the respective document of the aforementioned

documents and this specification can be met.

12.1.6 Use of high alloy steels, including austenitic stainless steels, shall be

on a case-by-case basis, with prior approval of the Saudi Aramco

Engineer as defined in this specification. Material selection shall be

based on the design temperature, minimum design metal temperature

and intended service.

12.1.7 All materials, except carbon steels, shall be alloy-verified by the

Vessel Manufacturer in accordance with SAES-A-206.

12.1.8 The use of C-½ Mo steels in hydrogen services is prohibited.

12.1.9 Material of construction (pressure-retaining and attachments used for

supporting or lifting the vessel) shall be tested, as applicable, to verify

that their mechanical properties will be retained considering all of the

following thermal treatments that could affect the material:

a) All heat treatment cycles that will be required for the fabrication

of the vessel, including as applicable: normalizing, normalizing

and tempering, quenching and tempering, intermediate stress

relief (ISR), and final postweld heat treatment (PWHT),

b) Two PWHT cycles to account for future repairs and/or

alterations.

12.1.10 As an alternative to material qualification requirements per paragraph

12.1.9 of this specification for carbon steel nozzles and standard

flanges according to ASME B16.5 and B16.47 that do not require

impact testing, materials of construction shall have minimum 70 MPa

(10 ksi) over their specified minimum yield strength and ultimate

tensile strength values.

12.1.11 Forgings shall meet a material cleanliness C2/R2/S2 rating, as

described in ASTM E381.

12.1.12 Specimens for material testing shall be taken per the following:

a) Plates

Specimens shall be taken from each plate transverse to the rolling

direction in accordance with SA-20 at the standard test locations





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and at a depth of ½T (T = maximum heat-treated thickness)

location. If required, ½T specimens should be used for hot

tensile and step cooling tests.

b) Plate-like forgings (forged rings, tubesheets, blind flanges, etc.)

Specimens shall be taken from each heat transverse to the major

working direction in accordance with the material specification,

and at a depth of ½T of a prolongation or of a representative

separate test block.

c) Standard flanges according to ASME B16.5 and B16.47.

1. For flanges with T equal to or less than 50 mm, specimens

shall be removed in accordance with the material specification.

2. For flanges with T greater than 50 mm, specimens shall be

removed in accordance with the material specification from a

production forging or a representative separate test block that

are machined to essentially the finished product configuration

prior to heat treatment. The center axis of the specimen shall

be at a depth of ½T and the mid-length of the test specimen

shall be at a depth at least equal to T from any second heat-

treated surface.

d) Other forgings that are contour shaped or machined to essentially

the finished product configuration prior to heat treatment, test

specimens shall be removed in accordance with the material

specification of a production forging or a representative separate

test block. The center axis of the specimen shall be at a depth of

½T and the mid-length of the test specimen shall be at a depth at

least equal to T from any second heat-treated surface.

e) Pipe

Specimens shall be taken from each heat and lot of pipe,

transverse to the major working direction in accordance with

used material specification except that test specimens should be

taken from a depth of ½T.

f) A separate test block, if used, should be made from the same heat

and should receive substantially the same reduction and type of

hot working as the production forgings that it represents.

It should be of the same nominal thickness as the production

forgings and shall be machined to essentially the finished product

configuration prior to heat treatment. The separate test forgings




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should be heat-treated in the same furnace charge and under the

same conditions as the production forgings.

12.1.13 Layered constructions are prohibited for all vessels.

12.1.14 Materials for pressure vessels for de-aeration service shall be in

accordance with NACE RP0590.

12.1.15 Materials for vessels exposed to SSC environments shall be in

accordance with the following:

a) Forged flanges and forged fittings are restricted to: SA-350 LF1

or LF2 or SA-266 Grade 4.

b) Flanges above 24-inch diameter shall be SA-266 Grade 4.

c) Studs are restricted to: SA-193 B7M or SA-320 L7M.

d) Nuts are restricted to: SA-194 Grade 2HM.

e) It shall satisfy the requirements of ISO 15156 and NACE RP0472.

12.1.16 Low alloy steels shall not be mixed. For example, a vessel requiring

1 Cr-½ Mo materials shall have all components manufactured from

1 Cr-½ Mo.

12.1.17 Low alloy steels shall be specified in the normalized and tempered

heat-treated or quenched and tempered conditions. Material of

construction shall be tested, as applicable, to verify that their

mechanical properties will be retained considering thermal treatments

specified in paragraph 12.1.9 of this specification.

12.1.18 Material for nameplate mounting brackets shall be of the same type

and material grade as the shell material.

12.1.19 SA-36 and SA-285 materials may be used only for pressure retaining

components of vessels in water and air services with plate thickness

not exceeding 19 mm.

12.1.20 Materials of supports shall be as follows:

1) Legs and lugs: same material as vessel wall base material.

Supports of vessels described in paragraph 12.1.19 of this

specification may be of the same ASME material P No. as that of

the vessel wall base material.

2) Skirts: same material as the vessel wall base material for a

minimum distance of 300 mm measured below the vessel-to-skirt




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connection line, unless thermal calculations require additional

length. Remaining section of skirt shall be of the same material

or same ASME material P No.

3) Saddles: same material as the vessel wall base material.

12.1.21 External attachments, other than those in paragraph 12.1.20 of this

specification, and internal attachments welded to the vessel shall be of

the same material as the vessel wall base material. With prior approval

of Saudi Aramco Engineer as defined in this specification, Stainless

Steel (SS) internal attachments can be welded to carbon steel pressure-

retaining parts of vessels in non-sour services.

12.1.22 Internal attachments to clad vessels shall be of the same material as

that of the cladding. SS 321 and SS 347 can be used interchangeably.

12.1.23 Material of construction for anchor bolts shall be ASTM A193 /

A193M, ASTM F1554 Grade 36 or ASTM F1554 Grade 105 with the

corresponding material of construction for nuts according to SASD

AA-036322.

12.1.24 One temper embrittlement test block shall be installed in hydrotreating

or hydrocracking reactors made of 2 ¼ Cr-1Mo, 2 ¼ Cr-1Mo- ¼ V,

3Cr-1Mo or 3Cr-1Mo- ¼ V. Test block shall be made from

prolongation of a shell ring or a shell plate used for constructing the

reactor shell. Test block shall be 300 mm long, 300 mm wide, and

have thickness same as the shell. Test block shall be weld overlaid

from 5 sides with the same welding procedures used to fabricate the

reactors. After weld overlay, test block shall be exposed to the

minimum post weld heat treatment cycle before attaching to a bottom

structure of the reactor. Fabricator shall provide the test block

attachment drawing for Saudi Aramco approval.

12.1.25 One manual UT test block and one TOFD UT test block shall be

provided by the fabricator of hydrotreating or hydrocracking reactors

made of 2 ¼ Cr-1Mo, 2 ¼ Cr-1Mo- ¼ V, 3Cr-1Mo or 3Cr-1Mo- ¼ V

with shell thickness greater than 150 mm. Test blocks shall be made

from prolongation of a shell ring or a shell plate used for constructing

the reactor. Test blocks shall be prepared in such a way that they can

be used to meet all fabricator’s UT calibration procedures and that

inspection according to API RP 934A, Appendix A can be performed

on site in a later date, if deemed necessary.

http://standards/docs/Standard_Drawings/PDF/AA-036322-001.PDF




Page 29 of 54

12.2 HIC Resistant Materials

Hydrogen Induced Cracking (HIC) resistant steel shall be qualified in accordance

with 01-SAMSS-016. HIC resistant steel shall be procured from Saudi Aramco

approved manufacturers within a list available by the Saudi Aramco buyer, as

defined in this specification.

12.3 Gasket Materials

Types and material specifications of gaskets shall be as specified on the data

sheet.

12.4 Impact Testing

12.4.1 The Vessel Manufacturer is responsible of determining the required

Charpy impact energy value(s) based on the test temperature specified

on the data sheet and the purchased vessel’s component thickness.

12.4.2 Impact test temperature for a component of a vessel shall be as


12.4.3 Minimum acceptable Charpy impact energy values for all materials of

construction (base and weld metals) shall not be less than the highest

of the following applicable values:

1) 40/32 Joules for carbon steels thicker than 50 mm

2) As specified by ASME SEC VIII D2, but not less than

34/27 Joules

3) As specified by the licensor’s specification, but not less than

34/27 Joules

4) 55/47 Joules for 1 Cr- ½ Mo, 1 ¼ Cr- ½ Mo, 2 ¼ Cr- 1 Mo, 2 ¼

Cr- 1 Mo- ¼ V, 3 Cr- 1 Mo and 3 Cr- 1 Mo- ¼ V steels.

Commentary Notes:

a) The first number of required energy values is the minimum average energy of three specimens and the second number is the minimum for one specimen of the impact test results. The second number shall not be less than 80% of the average value.

b) Minimum acceptable Charpy impact energy values are applicable to Div. 1 and Div.2 vessels.

12.4.4 For Div. 1 vessels the impact testing exemptions of UG-20 (f),

UCS-66 (b) (1) and (3), UCS-68(c), UG-84 (b) (2) and by reference to

Table UG-84.4 are not permitted. For Div. 2 vessels the exemptions of





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3.11.2.3, 3.11.2.4, 3.11.2.5, 3.11.2.6, 3.11.2.8, 3.11.2.10, 3.11.3.1 and

3.11.4 are not permitted.

12.4.5 Impact testing is required, with no exception, for pressure vessels made

of low alloy steels.

12.4.6 Impact testing of materials and welding procedures are required when

test temperature is lower than -28°C.

12.5 All forgings shall be forged as close as practicable to finished shape and size to

develop metal flow in a direction most favorable for resisting the stresses

encountered in service.

12.6 All flanges, fittings and piping for use as integral parts of pressure vessels shall

be purchased from Saudi Aramco approved manufacturers, either directly or

through approved stockists. Procurement of these items from stockists shall be

in accordance with SAEP-347.

13 Fabrication

13.1 Fabrication Tolerances

13.1.1 Fabrication tolerances shall be in accordance with the more stringent of

the applicable Code and PIP document VEFV1100, with the following

exceptions to tolerances on page 1 of drawing VEFV1102:

Tolerance 1: Height from base line to face of top nozzle shall be the

smaller of 4 mm per 3000 mm of height or 19 mm.

Tolerance 2: Flange face of nozzle with agitator shall be aligned

within ±¼ degree of indicated plan in any direction.

Tolerance 7: Unless more stringent tolerances are specified by the

process licensor, alignment of flange face of nozzle

without an agitator shall be within ±½ degree of

specified plan, but not to exceed 5 mm across the

diameter.

Tolerance 12: Bottom of vessel support to base line 0 mm, -6 mm.

Tolerance 13: For supports located above baseline, tolerances shall be

0 mm, + 6 mm.

Tolerance 14: Maximum difference in peak deviations from straight,

applied to the shell at any location along the

circumference clear of openings, shall be: 3 mm in any






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3000 mm of length, 12 mm in any 15000 mm of length,

and shall not exceed 19 mm over the overall length of

shell. In addition, distortion caused by welding of

longitudinal or circumferential joints shall not exceed

6 mm maximum depth in a 900 mm length of shell

centered on the weld.

Tolerance 20: Deviation from average I.D. (as determined by

strapping) from nominal I.D. shall be as follows:

a) ±3 mm for I.D. ≤ 1200 mm

b) ±6 mm for I.D. > 1200 mm

Out-of- roundness tolerances shall be according to

applicable ASME SEC VIII.

Tolerance 26: Supports out of level shall be within ±3 mm.

Deviation from flatness of support base plate is not

acceptable, i.e., support base plates shall be in full

direct contact with the foundation.

Tolerance 28: Delete.

Tolerance 31: Distance between centerlines of support bolt holes

shall be within ±6 mm and maximum diagonal

measurements shall be within ±6 mm.

13.1.2 Use of fitness-for-service assessment methodology to qualify the

design of components that do not satisfy the fabrication tolerances

according to this specification is prohibited.

13.1.3 Dished heads shall achieve at least the minimum required thickness in

all areas after forming.

13.2 Forming and Assembly

13.2.1 Tapered transitions shall be made only on the external surface of the

vessel, according to the rules of the applicable Code, in the following

conditions:

a) There will be an interference with the removal of a vessel's

internals.

b) Vessels that have strict requirements regarding smooth internal

profiles for flow or cyclic loading conditions or internal volume

constraints.




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13.2.2 The beveled edges of weld preparations for carbon steel plates with

thickness 25 mm and thicker and all ferrous alloy plates shall be

magnetic particle examined for linear discontinuities. Defects shall not

exceed limits as per ASME SA-20.

13.2.3 Plate edge laminations revealed by magnetic particle examination shall

be completely removed and repaired.

13.2.4 Each shell section shall be completely welded longitudinally and

corrected for out of roundness and peaking of the weld seam prior to

welding to adjoining shell or head.

13.2.5 All re-rolling or forming of the shell sections is to be completed prior

to radiography.

13.2.6 Welds Encroachment

13.2.6.1 It is the responsibility of the manufacturer to ensure that the

outer edge of welds attaching manways, nozzles (with and

without reinforced pads) and other structural attachments

(with and without reinforced pads), except those in paragraph

10.2.11, to pressure-retaining components shall not be closer

than 1 inch from the adjacent edge of any other weld. It is the

responsibility of the manufacturer to ensure that requirements

of paragraph 7.11.4 of this specification are met in the vicinity

of the welds.

Commentary Note:

Weld spacing requirements for skirt-to-vessel junctures shall be according to paragraph 10.2.11 of this specification.

13.2.6.2 Where the optimized fabrication layout and/ or process design

requirements do not absolutely allow meeting the spacing

requirement in paragraph 13.2.6.1 of this specification, NDE

per paragraph 14.6 shall be performed.

13.2.6.3 It is prohibited to cover butt welds in wall of vessels that will

undergo PWHT by structural attachments (with or without

reinforcing pads).

13.2.7 Telltale Holes in Reinforcing Pads

13.2.7.1 ¼ - inch telltale vent holes drilled and tapped for ⅛ -inch NPT

shall be provided in reinforcing pads for welded attachments,

including nozzles and manways, per the following:




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1) One hole in single piece reinforcing pad.

2) Where a pad is split, each segment shall have at least

one hole.

13.2.7.2 Telltale holes shall be located at the lowest position

accessible for inspection with center of the hole 25 mm

from edge of the pad. This is applicable to each segment of

a split reinforcing pad.

Commentary Note:

In case of reinforcing pads for attachments, other than nozzles and manways, center of telltale hole shall be 25 mm from the closest edge of the pad.

13.2.7.3 Telltale holes in reinforcing pads for external welded

attachments shall be plugged with grease or other materials

adequate for the operating temperature but not capable of

retaining pressure, to prevent moisture ingress between the

pad and the vessel pressure-retaining component. Telltale

holes in internal attachment pads shall be seal welded.

13.2.8 Segments of split reinforcing pad shall be welded together without

using a backing strip.

13.2.9 All internal and external attachments, including clips, welded directly

to pressure-retaining parts, shall be fully seal welded, except for blank

square nuts used for external insulation where tack welding is allowed.

13.2.10 No tack welding is permitted between heads and skirts on the inside of

skirts.

13.2.11 Vessels with large diameter and/ or overall length which fabrication

cannot be completely done in shop shall be designed to minimize the

amount of field welding, radiography and heat treatment. Where

adjacent sections are of such a size that shop fabrication and field

assembly is required, the sections shall be match marked to ensure

proper field fit up.

13.2.12 Forming

13.2.12.1 General

a) Cold forming is performed at temperatures within the

range of above 20°C (68°F) and below 120°C (248°F).




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b) Hot forming is any forming performed above the

austenite phase start temperature of 740°C (1364°F).

c) All tempering heat treatments must be at least 25°C

(45°F) above the nominal PWHT temperature as

given in the applicable ASME code for the respective

material.

13.2.12.2 Hot Forming

1) All quenched and tempered materials must be

completely heat-treated after hot forming to achieve

the original material properties.

2) All hot forming procedures require approval of the

Saudi Aramco Engineer as defined in this

specification prior to commencement of any of

forming activities. Hot forming procedure shall

describe all heat treatment operations and tests to be

performed. The tests shall include, but not limited to,

all of the mechanical tests required by the original

material specification.

3) Normalized materials that are hot formed need to be

heat treated unless the below rules are followed:

a) Normalized materials that are hot formed in the

range of 750°C (1382°F) to 950°C (1742°F) and

still air-cooled.

b) Normalized materials that are hot formed in a

multi-step sequence must be cooled to below 200°C

(392°F) prior to the last step. The material will then

be re-heated within the range of 750°C (1382°F) to

950°C (1742°F) for forming in the last step.

c) Normalized and tempered materials that are formed

in accordance with either 13.2.14.2(3)(a) or

13.2.14.2(3)(b) of this specification need only

receive a tempering heat treatment. The tempering

temperature must not exceed the temperature stated

in the steel manufacturers Material Test Certificate.

13.2.12.3 Cold Forming

a) Heat treatment requirements for Carbon Steels (P-1)

and Low Alloy Steels (P-3, 4, 5, 9A and 9B) that




Page 35 of 54

undergo cold forming (by pressing or cold spinning)

shall be as follows:

Material Fiber Elongation Strain εf (%) Heat Treatment Requirement

Carbon Steels P-1

Less than or equal to 5

None

(Exception: PWHT per the applicable Code shall be performed for cold spun heads)

Greater than 5 and equal to or less than 10

PWHT per the applicable Code

Greater than 10 Normalizing, Normalizing and tempering or quenching and tempering, as required to maintain original material properties.

Low Alloy Steels P-3, P-4, P-5, P-9A & P9B

Less than or equal to 3

None

(Exception: PWHT per the applicable Code shall be performed for cold spun heads)

Greater than 3 and equal to or less than 10

PWHT per the applicable Code

Greater than 10 Normalizing, normalizing and tempering or quenching and tempering, as required to maintain original material properties.

High Alloy Materials Table 6.2 of ASME Section VIII,

Division 2 Table 6.2 of ASME Section VIII, Division 2

Non-ferrous Materials Table 6.3 of ASME Section VIII,

Division 2 Table 6.3 of ASME Section VIII, Division 2

b) Calculation of forming fiber elongation strain εf (%)

shall be according to the following:

Type of Part Being Formed Fiber Elongation Strain εf (%)

For double curvature heads that are formed from

one-piece or welded multi-piece blanks by any

process that includes dishing or cold spinning (e.g.,

dished heads or cold spun heads)

εf = 100 ln [Db/(Df -2ta)]

For heads that are assembled from formed segments

(e.g., spherical dished shell plates or dished segments

of ellipsoidal or torispherical heads)

εf = 100 tb / Rfd

Cylinders and cones formed from plate εf = (50 tb / Rfc) [1-(Rfc / Ro)]

Where:

ln is the natural logarithm

Db is the diameter of unformed blank plate or diameter of intermediate product

Df is original outside diameter




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Rfd is the smallest mean radius of curvature of formed segment (mean radius of spherical

segment, mean knuckle radius of knuckle segment of multi sectional semi-ellipsoidal or

torispherical heads)

Rfc is the mean radius of curvature of finished product (mean radius of cylinder, mean

radius of the smaller diameter of cone)

Ro is the mean radius of initial product (flat plate) or the intermediate product (in case of

unformed initial product equals to infinity)

ta is the nominal thickness of the plate before forming or intermediate product

tb is the nominal thickness of the plate before forming

Commentary Notes:

i) Cold spun heads with nominal thickness exceeding 50 mm shall be heat treated by normalizing, normalizing and tempering or quenching and tempering, as required to maintain original material properties), irrespective of the calculated fiber elongation strain.

ii) For semi-ellipsoidal and torispherical heads formed from one-piece or welded multi-piece blanks, maximum calculated extreme fiber elongation strain among all head’s zones shall be used to determine the need of heat treatment. Separate calculation for each zone (spherical crown, knuckle area, etc.) shall be made, using the greatest measured thickness and smallest radius of curvature of the zone after forming.

iii) Separate calculation of extreme fiber elongation shall be made for each formed segment (e.g., spherical dished shell plates or dished segments of ellipsoidal or torispherical heads). Need for heat treatment shall be determined for each segment individually using the greatest measured thickness and smallest radius of curvature after forming.

iv) In case of different forming steps without intermediate heat treatment are employed, extreme fiber elongation is the total amount of elongation of the individual forming steps. In case of intermediate heat treatment, the deformation is that elongation achieved after the last previous heat treatment. This is applicable for all types of formed part.

v) Filler metal used in items subjected to hot forming temperatures, or normalized, shall satisfy the weld joint design requirements after such heat treatment. This is considering that such welds will generally suffer significant strength reduction.

13.2.13 Bolt tensioning device shall be used for bolting up flanged connections

with stud bolts of diameter 1-½ inch and above. Bolt up of flanges,

irrespective of bolt diameter shall be according to ASME PCC-1

requirements.

13.2.14 Correction of fit-up offsets of the closing longitudinal butt joint in a

rolled shell ring shall be achieved by only employing rolling machine

operation until the deviations are within the specified Code tolerances.




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13.2.15 Alignment of pre-formed sections of multi-piece vessel head at butt

joints, with fit-up deviations exceeding the Code tolerances, shall be

achieved by only reforming (employing pressing machine) the head

segments until the deviations are within the specified limits.

13.2.16 Alignment of completely fabricated sections at girth joints (shell ring-to-

shell ring and head-to-shell ring), with fit-up deviations exceeding the

Code tolerances, shall be achieved by only reforming the shell (using

rolling machine) or head (employing pressing machine), whichever is

out-of-true, until the deviations are within the specified limits.

13.3 Welding

13.3.1 All welding shall be in accordance with the requirements of

SAES-W-010.

13.3.2 Dissimilar metal welds (DMW) are not permitted in sulfide stress

cracking environment as defined in this specification. Welds in clad

systems are acceptable if the DMW interface with the ferritic steel is

not in contact with the sour fluid.

13.3.3 Following maximum allowable carbon equivalent, based on thickness

(t) shall be met for pressure vessels intended for sulfide stress cracking

environment.

Thickness (mm) Carbon Equivalent (%)

6 < t < 60 0.43

60 < t < 100 0.45

t > 100 0.48

13.3.4 The method of weld overlay shall be such as to produce a minimum of

3.2 mm thickness meeting the specified chemical composition of the

specified weld overlay material.

14 Nondestructive Examination

14.1 General

14.1.1 All required Nondestructive Examination (NDE) shall be performed in

accordance with inspection procedures that are in complete compliance

with ASME SEC V and this specification. This written procedure shall

address each inspection method and technique used including

acceptance criteria. When required by the purchase order or this





Page 38 of 54

specification the procedure(s) shall be submitted to Saudi Aramco

Inspection Department for approval.

14.1.2 All Nondestructive Examination, including Magnetic Particle and Liquid

Penetrant examinations, shall be performed by personnel certified in

accordance with ASNT CP-189, or equivalent National Certification

Programs that has been approved by the Saudi Aramco Inspection

Department. Personnel responsible for interpretation of Nondestructive

Examination results shall be certified to a minimum of Level II.

14.1.3 All required NDE for final acceptance of the vessel shall be performed

after the completion of all welding and repairs and prior to pressure

testing. In vessels requiring PWHT, all NDE for final acceptance shall

be performed after the final PWHT.

14.1.4 All pressure and non-pressure welds shall be visually inspected where

accessible. All segments of longitudinal, circumferential or built-up

head pressure weld seams covered or rendered inaccessible by

internals, lifting lugs or other attachments shall be fully radiographed

over the entire affected length plus minimum 5 cm (2 inches) either

side prior to installation of the attachment.

14.1.5 Magnetic particle examination or liquid penetrant examination per the

applicable Code shall be performed on the surfaces of hot formed and

reheat treated parts.

14.2 Radiographic Examination

14.2.1 All radiography shall be performed with intensifying screens. Only lead

or lead foil (fluoro-metallic) screens shall be permitted unless otherwise

approved by the Saudi Aramco Inspection Department.

14.2.2 Tungsten inclusions in Gas Tungsten Arc welds shall be evaluated as

individual rounded indications. Clustered or aligned tungsten

inclusions shall be removed and repaired.

14.2.3 Radiography examination requirements for weld joints categories A, B,

C and D shall be according to Table 1 of this specification and the

following:

a) Butt welds connecting forged junction ring, conforming to

ASME SEC VIII D2, Figure 4.2.4(e), to shell and head shall be

100% radiographed. Use of ultrasonic examination method that

generates permanent records can be used as a substitute to

radiography, as applicable (see relevant requirements per Note 3

of Table 1).




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b) Butt welds in multi-piece plate blanks to be formed into heads

shall be 100% radiographed after forming. Use of ultrasonic

examination method that generates permanent records can be

used as a substitute to radiography (see relevant requirements per

Note 3 of Table 1).

14.2.4 100% radiography examination is required for the following weld joints:

a) Butt welds connecting skirt to forged junction ring, conforming

to ASME SEC VIII D2, Figure 4.2.4(e).

b) Butt welds connecting skirt to weld build-up construction at

vessel-to-skirt junction per paragraph 10.2.9 of this specification.

c) Butt welds connecting forged junction ring according to

ASME SEC VIII D2, Table 4.2.5 - Detail 7 to shell and head.

14.3 Ultrasonic Examination

14.3.1 Ultrasonic examination requirements for weld joints categories A, B, C

and D shall be according to Table 1 of this specification.

14.3.2 All plates in thick wall vessels shall be ultrasonically examined by the

Vessel Manufacturer in accordance with ASTM SA578. Acceptance

criteria shall be Level C of SA-578.

14.3.3 Plates with thickness more than 12.5 mm (0.5 inch) shall be

ultrasonically examined by the vessel manufacturer in accordance with

ASME SA-435. Any area where one or more discontinuities produce a

continuous total loss of back reflection accompanied by continuous

indications on the same plane (within 5 % of plate thickness) that

cannot be encompassed within a 25 mm (1 inch) diameter circle is

unacceptable.

14.3.4 100% Ultrasonic examination is required for the following weld joints:

a) Butt-welds in vessel supports.

c) Full-penetration welds in external attachments (supports,

brackets, lugs, etc.) to pressure retaining parts.

14.3.5 All forgings shall be 100% ultrasonically examined by the equipment

manufacturer in accordance with ASME SA388. Acceptance criteria

shall be in accordance with ASME SEC VIII D2, paragraph 3.3.4.2.

Indications per ASME SEC VIII D2, paragraphs 3.3.4.3 and 3.3.4.4 are

not acceptable.




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14.3.6 100% ultrasonic examination is required for welds attaching vessel

directly to skirt and conforming to ASME SEC VIII D2,

Figures 4.2.4(a), 4.2.4(b) and 4.2.4(c). Where ultrasonic examination

cannot be utilized, due to only construction geometric configuration,

the whole joint shall be either magnetic particle (MP) or liquid

penetrant (LP) examined after each 6 mm depth of weld deposit and

the finished weld surface.

14.3.7 100% conventional ultrasonic examination is required for all full

penetration welds in vessel supports. Alternatively, 100% radiography

examination shall be used.

14.3.8 Weld build-ups construction at vessel-to-skirt junction per paragraphs

10.2.9 and 10.2.10 of this specification shall be 100% ultrasonically

examined.

14.4 Magnetic Particle Examination

14.4.1 Permanent magnetic yokes are not permitted.

14.4.2 Prods are not permitted for use on air-hardenable materials, materials

that require impact testing, and on the fluid side of pressured

components for vessels in wet sour service.

14.4.3 Except for non-Ferro magnetic materials, magnetic particle

examination using an AC yoke is required for the following welds:

a) Pressure containing weld joints categories A, B, C and D per

Table 1 of this specification.

b) Welds in vessel support (skirt, saddle, lug, and leg)

c) Attachment welds to the pressure vessel

d) Areas where temporary attachments have been removed

e) Arc strike areas

Internal welds shall be examined with Wet fluorescent MPI. External

welds shall be examined with wet visible MPI or Wet fluorescent MPI

(Note: if wet visible MPI is used, a white color contrast coating shall

be applied prior to the examination).

14.4.4 All edges prepared for welding and all openings shall be magnetic

particle examined in accordance with the applicable Code.

14.4.5 Forgings shall be examined on all surfaces, utilizing wet fluorescent

magnetic particle method after final machining. All defects shall be




Page 41 of 54

removed and repaired by welding in accordance with SAES-W-010.

Exception:

Except for welding edges, liquid penetrant examination is acceptable as an alternative to magnetic particle examination.

14.5 Liquid Penetrant Examination

For non-Ferro magnetic materials, liquid penetrant examination shall be used for

the following welds:

a) Pressure containing welds joints categories A, B, C and D per Table 1 of

this specification.

b) Welds in vessel support (skirt, saddle, lug, and leg)

c) Attachment welds to the pressure vessel

d) Areas where temporary attachments have been removed

e) Arc strike areas

14.6 Welds Encroachment

Where the optimized fabrication layout and/ or process design requirements do

not absolutely allow meeting the spacing requirement in paragraph 13.2.6.1 of

this specification, NDE per the following table shall be performed.

Case PWHT is required ( Note 1) PWHT is not required

1. Nozzle or manway without a reinforcing

pad installed onto a butt weld in vessel wall

RT of butt weld in vessel for a length equal

to three times the diameter of the opening with the center of the opening at mid-length.

Same as when PWHT is required.

2. Nozzle or manway with a reinforcing pad installed onto a butt weld in vessel

wall

N/A

(See paragraph 8.5.2 of this specification)


to three times the diameter of the opening with the center of the opening at mid-length.

The butt weld shall be ground flush prior to

installation of the pad.

3. Nozzle or manway, without a reinforcing pad, encroaching on a butt

weld in vessel wall

RT of butt weld in vessel for a length equal to three times the diameter of the opening

with the center of the opening at mid-length.


4. Reinforced nozzle or manway with the

reinforcing pad encroaching on the butt

weld in vessel wall

N/A



to three times the diameter of the opening


5. Reinforced nozzle or manway with

penetration encroaching the butt weld

and the reinforcing pad covering it

N/A


RT of butt weld in vessel for a length equal to three times the diameter of the opening


The butt weld shall be ground flush prior to installation of the pad.





Page 42 of 54

Case PWHT is required ( Note 1) PWHT is not required

6. Structural attachment, without a reinforcing pad, encroaching on a butt

weld in vessel wall


to the projection of the attachment weld plus a minimum of 50 mm on either side.

Minimum length of the radiographed weld is

12 inches.


7. Reinforced structural attachment, with

the reinforcing pad encroaching on a butt weld in vessel wall


to the projection of the reinforcing pad

attachment weld plus a minimum of 50 mm on either side. Minimum length of the

radiographed weld is 12 inches.


8. Structural attachment, without a

reinforcing pad, covering a butt weld in

vessel wall

N/A

(See prohibition in paragraph 13.2.6.3 of this

specification)

RT of butt weld in vessel for a length equal to the projection of the reinforcing pad

attachment weld plus a minimum of 50 mm

on either side. Minimum length of the radiographed weld is 12 inches.

9. Reinforced structural attachment, with the reinforcing pad covering a butt weld

in vessel wall

N/A

(See prohibition in paragraph 13.2.6.3 of this

specification)


to the projection of the reinforcing pad

attachment weld plus a minimum of 50 mm on either side. Minimum length of the

radiographed weld is 12 inches. The butt

weld shall be ground flush prior to installation of the pad.

10. Structural attachment (with or without

reinforcing pads) encroaching:

a) Another structural attachment (with or

without reinforcing pads)

b) Reinforced nozzle or manway

c) Nozzle or manway without a

reinforcing pad

MP or LP on the entire outermost fillet weld of each attachment on the vessel side per

paragraph 14.4 or 14.5, as applicable, after

completion of all welds in all attachments.


Note 1: NDE for final acceptance of the vessel shall be performed after the final PWHT per paragraph 14.1.3 of this

specification.

14.7 Hardness Testing

Weld hardness testing shall be in accordance with the requirements of

SAES-W-010.

15 Postweld Heat Treatment

15.1 Postweld heat treatment shall be done when required by the applicable Code or

when specified on the data sheet.

15.2 Code exemptions for postweld heat treatment of ferritic materials based on the

use of austenitic or nickel-based electrodes are not permitted for vessels in

sulfide stress cracking environments as defined in this specification.

15.3 Code exemptions for postweld heat treatment of P4 and P5 materials are not

permitted for applications involving either wet sour or hydrogen services or for

materials exceeding 1.25% nominal chromium content.





Page 43 of 54

15.4 The maximum postweld heat treating soaking temperature for quenched and

tempered carbon steel materials shall not exceed the temperature at which the

test pieces were heat treated, as shown on the Mill Test Reports or 650°C

maximum for carbon steel and 700°C for low chrome alloy steels.

15.5 Time and temperature of post weld heat treatment for carbon steel vessel with

potential environmental cracking shall be in accordance with requirements of

API RP582.

15.6 Final postweld heat treatment shall follow all welding and repairs but shall be

performed prior to any hydrotest or other load test.

15.7 A sign shall be painted on a postweld heat treated vessel and located such that it

is clearly visible from grade reading:

“Caution-Vessel Has Been Postweld Heat Treated-Do Not Weld”

15.8 Postweld heat treatment shall be in accordance with the requirements of

SAES-W-010 and this specification.

16 Examination, Inspection, Pressure Tests and Repairs

16.1 Examination

16.1.1 The responsibility for examination rests with the Vessel Manufacturer

in accordance with the applicable Code and the requirements of this

specification.

16.1.2 Additional examination of any weld joint at any stage of the fabrication

may be requested by the Saudi Aramco Inspector, including repeating

examination of previously examined joints. The Saudi Aramco

Inspector also has the right to request or conduct independent

Nondestructive Examination of any joint. If such examination should

disclose nonconformance to the requirements of the applicable Code or

this specification, all repair and Nondestructive examination costs shall

be done at the Vessel Manufacturer's expense.

16.1.3 All necessary safety precautions shall be taken for each examination

method.

16.1.4 Surface irregularities, including weld reinforcement, inhibiting

accurate interpretation of the specified method of nondestructive

examination shall be ground smooth.

16.1.5 Examination of all welds shall include a band of base metal at least one

inch wide on each side of the weld.





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16.2 Inspection

16.2.1 The Saudi Aramco Inspector shall have free access to the work at all

times.

16.2.2 Saudi Aramco shall have the right to inspect the fabrication at any

stage and to reject material or workmanship, which does not conform

to the specified requirements.

16.2.3 Saudi Aramco reserves the right to inspect, photograph, and/or

videotape all material, fabrication, coating, and workmanship and any

materials, equipment, or tools used or to be used for any part of the

work to be performed.

16.2.4 Saudi Aramco may reject the use of any materials, equipment, or tools

that do not conform to the specification requirements, jeopardize safety

of personnel, or impose hazard or damage to Saudi Aramco property.

16.2.5 All of the rights of Saudi Aramco and their designated representatives

for access, documentation, inspection, and rejection shall include any

work done by sub-contractors or sub-vendors.

16.2.6 The Vessel Manufacturer shall provide the Saudi Aramco Inspector all

reasonable facilities to satisfy him that the work is being performed as

specified.

16.2.7 The fabricator shall furnish, install, and maintain in a safe operating

condition all necessary scaffolding, ladders, walkways, and lighting for

a safe and thorough inspection.

16.2.8 Pressure vessels manufactured in accordance with this specification are

subject to verification by the Saudi Aramco Inspector in accordance

with Saudi Aramco Inspection Requirements Form 175-321900,

Manufacture of Pressure Vessels.

16.2.9 Prior to final inspection and pressure testing, the inside and outside of

the vessel shall be thoroughly cleaned of all slag, scale, dirt, grit, weld

spatter, paint, oil, etc.

16.2.10 Inspection at the mill, shop, or fabrication yard shall not release the

Vessel Manufacturer from responsibility for repairing or replacing any

defective material or workmanship that may be subsequently

discovered in the field.

http://standards/docs/Inspection_Requirements/PDF/175-321900.PDF




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16.3 Pressure Testing

16.3.1 After completion of all external and internal welding, nondestructive

examination, repairs and heat treatment, as applicable, and prior to

painting, vessels shall be pressure tested using water as the testing

media in accordance with the applicable Code, SAES-A-007 and this

specification.

16.3.2 Pneumatic testing in lieu of hydrostatic testing requires the approval of

the Manager of the Saudi Aramco Inspection Department.

16.3.3 Hydrostatic test pressure shall be held for a minimum of one hour per

25 mm of vessel thickness and in no case less than one hour.

16.3.4 Pressure testing for acceptance of the vessel shall not be made prior to

the final postweld heat treatment.

16.3.5 All welded attachments provided with telltale holes shall be

pneumatically tested at minimum 70kPa (10 psi) prior to heat treatment

and vessel pressure testing.

16.3.6 Telltale holes in external attachments must not be plugged during the

vessel pressure test. Telltale holes in internal attachments must be seal

welded prior to pressure testing of the vessel.

16.3.7 The use of shellacs, glues, lead, etc., on gaskets during testing is

prohibited. No paint or primer shall be applied to a vessel prior to

hydrostatic testing.

16.3.8 The Vessel Manufacturer shall furnish all test materials and facilities,

including blinds, bolting, and gaskets.

16.3.9 Hydrostatic pressure testing shall be performed with gaskets and bolting

identical to those required in service and as specified on the data sheet.

These gaskets may be used as service gaskets if the bolted joint is not

disassembled after completion of hydrostatic pressure testing.

16.3.10 The manufacturer shall supply the following:

a) Minimum two sets of spare gaskets with a blind flange for each

manway and blinded nozzle in the vessel.

b) Minimum one set of service gasket set and two sets of spare

gaskets for each nozzle with companion flanges in the vessel.

c) All bolting with minimum 10% spare bolting (3 minimum for

each size) per vessel.





Page 46 of 54

16.3.11 Test pressure measured at the top of the vessel shall be:

16.3.11.1 For Division 1 vessels per UG-99(b):

PT=1.3 MAWP (S/ST)

16.3.11.2 For Division 2 vessels per 8.2.1:

Greater of:

i) PT = 1.43 MAWP

ii) PT = 1.25 MAWP (ST/ S)

Where,

PT is the minimum test pressure

S is the allowable stress at design temperature

ST is the allowable stress at test temperature

ST/S is the lowest ratio for the pressure boundary

materials, excluding bolting materials, of which

the vessel is constructed.

16.3.12 Water used for pressure testing shall be potable. For vessels

manufactured from stainless steel, the water shall not contain more

than 50 ppm chlorides with pH value not exceeding 7 at the time of

filling the vessel.

16.3.13 Temperature of water during hydrostatic testing shall be maintained at

not less than 17°C throughout the testing cycle.

16.3.14 Vertical vessels that are pressure tested in the horizontal position shall

be adequately supported such that the primary stresses in any part of

the vessel do not exceed 90% of the minimum specified yield strength

of the vessel material.

16.3.15 Horizontal vessels shall be tested while resting on their permanent

support saddles without additional supports or cribbing.

16.3.16 Vessels shall be protected from being over pressured, while being

pressure tested, by use of pressure test relief valve(s) meeting the

following:

a) Relief valves shall be of adequate capacity set to relieve at 10%

above the test pressure, provided requirements of paragraph

7.12.3 are met.




Page 47 of 54

b) Sizing of relief valve(s) shall be according to API RP520, Part I.

c) The relief valve(s) shall be tested, dated, and tagged within one

week prior to the pressure test.

d) The pressure test relief valve shall be accompanied with a

calibration certificate that includes the cold differential test

pressure (CDTP), test date and the spring range. The CDTP shall

be within the spring range.

16.3.17 After completion of pressure testing, the vessel shall be completely

drained and thoroughly dried including surfaces of internals.

For vessels made completely of stainless steels and vessels internally

cladded or weld-overlaid with these materials, pickling and passivation

shall be applied according to ASTM A380.

16.4 Manufacturing Repairs

16.4.1 The Saudi Aramco Engineer must review and approve crack repair

procedures, required by the applicable Code, prior to commencement

of repairs. It is the responsibility of the manufacturer to ensure that

repairs done by the mill of any material defects, per the applicable

Code, are documented.

16.4.2 After completion of repairs required by the applicable Code the

following shall be repeated:

a) Heat treatment of the repaired section if it has been heat-treated

prior to the repairs.

b) All nondestructive examinations (radiography, magnetic particle,

dye-penetrant, etc.) performed on the repaired section prior to the

repairs.

c) A weld map of all repairs shall be made a part of the final vessel

documentation. The weld map shall include the nondestructive

examination procedure and results, the welding procedure

specifications and stress relief charts.

17 Nameplates and Stampings

17.1 Each vessel shall be identified by a nameplate and marked with the information

required by the applicable Code and the requirements of this specification.

17.2 Vessels manufactured inside and outside Saudi Arabia shall be Code stamped

for all services in accordance with the applicable Code.




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17.3 Nameplates and nameplate mounting brackets shall be located such that they

will not be covered by insulation and are easily readable from grade or a

platform. Brackets shall extend from the outside of vessel to clear insulation,

and with sufficient access for surface preparation, and painting. The nameplate

markings as required by the applicable Code shall be stamped or engraved such

that the nameplate material is permanently deformed with the symbols.

17.4 Nameplates shall be 3-mm minimum thickness and manufactured from type 304

stainless steel or Monel and continuously welded to the mounting bracket

according to PIP VEFV1100.

17.5 The mounting bracket shall be continuously seal-welded and positioned such as

not to allow for collection of moisture or rain.

17.6 Nameplate for internally coated vessels shall show: the Saudi Aramco Painting

System Numbers, type of coating, brand name, and date of application.

18 Coatings and Painting

18.1 Type of coating and painting systems shall be as specified on the Vessel data

Sheet.

18.2 Surfaces to be coated shall be cleaned and prepared prior to its coating in

accordance with SAES-H-100.

18.3 Gasket contact surfaces shall be properly protected from blasting and shall not

be coated or painted.

19 Shipping Requirements

19.1 General

19.1.1 Vessel shall be protected against corrosion during shipping and at

fabrication yard and construction sites.

19.1.2 Prior to shipping, vessels are to be completely and thoroughly dried

and cleaned from all loose scales, weld slags, dirt and debris to the

satisfaction of the Saudi Aramco Inspector.

19.1.3 The Vessel Manufacturer is responsible for ensuring that the vessels

and internals being shipped are adequately braced and shall provide

temporary supports where appropriate to ensure adequate supporting of

the vessel during shipment.


http://standards/docs/SAES/PDF/SAES-H-100.PDF




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19.1.4 Vessels partially shop fabricated and/or liable to suffer distortion

during transit and erection shall be suitably braced. All ends that will

be open during shipment shall be covered to prevent ingress of dirt and

other foreign matters. The Vessel Manufacturer shall advise the Saudi

Aramco Engineer of the method of protection for review and approval.

19.1.5 Markings shall be done with water-insoluble materials that contain no

harmful substances that would attack or harmfully affect the vessel at

both ambient and design temperatures.

19.1.6 Marking materials shall be free of lead, sulfur, zinc, cadmium,

mercury, chlorine, or any other halogens.

19.1.7 Export packaging marking and shipping shall be in accordance with

the purchase order.

19.2 Internal Protection

19.2.1 Thoroughly dry the internal surface of the vessel. Remove all free

water. Thoroughly purge vessel with dry air so that relative humidity

inside vessel is less than 40% at the lowest ambient temperature likely

to be experienced in shipping and storage.

19.2.2 The interior surfaces of vessels, including internals, shall be protected

from corrosion by the use of a nontoxic liquid or powder vapor phase

corrosion inhibitor (VpCI) that is compatible with the metallurgy of all

components in the equipment being protected and is environmentally

friendly for disposal at sea. The chemistry shall be based on amine

carboxylates, amine benzoates, or amine oleates with additional

components as necessary. Nitrites shall not be used.

Following are specific requirements for corrosion inhibitors:

19.2.2.1 Water-soluble liquid products shall provide both vapor phase

and contact inhibition. These products shall be applied at the

rate of 1 liter per cubic meter of internal space or the

minimum specified by the inhibitor manufacturer, whichever

is greater. Liquid products are preferred as these are easily

removed with the process flow on start up.

19.2.2.2 Ready to spray, oil soluble liquid vapor phase corrosion

inhibitors can be used at a surface application rate of 25 to

30 square meters per liter of chemical, or the minimum

application rate recommended by vendor, whichever is greater.




Page 50 of 54

Oil soluble inhibitors will leave an oily film on the interior of

the equipment that must be acceptable to the end user.

19.2.2.3 Powders shall be free flowing crystals for ease of application

and be environmentally friendly for disposal at sea if

necessary. Powder products shall be applied at the rate of

0.3 kg per cubic meter of internal void space or the

minimum specified by the inhibitor manufacturer, whichever

is greater. Powder can be fogged into the equipment or it

can be placed inside Tyvek bags and then placed inside the

equipment. Tyvek bags must be removed before start-up.

For gas and LNG service, excess loose powder must be

removed before start-up by vacuuming or by water rinsing.

19.2.2.4 Products shall be tested per NACE TM0208-2008 and shall

provide Grade 3 or Grade 4 performance. When the equipment

contains a copper/copper alloy component, the VpCI shall also

be tested per Section 7 of NACE TM0208-2008.

19.2.2.5 For any questions on application rates, or any situations

requiring clarification or for approval of other products,

forms, or chemistries of vapor phase corrosion inhibitors,

obtain the prior written approval of the Supervisor,

Corrosion Technology Unit, Materials Engineering and

Corrosion Control Division, CSD.

19.2.2.6 Vessels must be sealed vapor tight using metallic covers, for

inhibitors to be effective.

19.2.3 For vessels made completely of stainless steels and vessels internally

cladded or weld-overlaid with these materials, in addition vapor phase

corrosion inhibitors applied per 19.2.2, nitrogen blanketing shall be

used during shipment or periods of storage at the construction site.

To apply nitrogen blanketing, pressurize the vessel to 60 psig with

nitrogen and bleed down slowly to 5 psig. Pressurization in this

manner shall be repeated 3 times. Bleed down must be slow and

controlled to minimize the loss of vapor phase inhibitor. The vessel

shall be clearly marked with a warning:

“Warning: asphyxiation hazard--preserved with nitrogen.”

19.2.4 For vessels that have permanent internal coatings covering some or all

of the vessel internals, the Vessel Manufacturer shall contact the

Supervisor, Corrosion Technology Unit, Materials Engineering and




Page 51 of 54

Corrosion Control Division, CSD, and obtain prior written agreement

on required preservation techniques.

19.2.5 Use of non-toxic desiccants is considered acceptable as an alternative

internal protection measure against corrosion for vessels ONLY when

the warranty will be revoked by using non-toxic vapor phase inhibitor;

provided that the following conditions are met:

19.2.5.1 The plan is pre-approved in writing by the Supervisor,

Corrosion Technology Unit, Materials Engineering and

Corrosion Control Division, CSD.

19.2.5.2 Silica gel application rate shall be a minimum of 3.0 kg per

cubic meter of internal space.

19.2.5.3 The vessel shall be maintained 100% vapor tight using

bolted metal blind flanges.

19.2.5.4 The plan includes methods and designated responsible

persons to evaluate the condition of the desiccant and re-

apply if necessary.

19.2.5.5 Calcium chloride desiccants shall not be used.

19.2.5.6 The desiccant must be removed on site prior to operating the

vessel.

Commentary Note:

These circumstances have arisen in the past when a vessel is shipped from a manufacturer with a catalyst in place prior to field erection.

19.2.6 Other preservation products or methods may be applied with the prior

written approval of the Supervisor, Corrosion Technology Unit,

Materials Engineering and Corrosion Control Division, CSD.

19.3 External Protection

19.3.1 The protection of external surfaces shall be obtained by using one of

the following:

a) A hard temporary preservative appropriate for the metallurgy of

the vessel and can be easily removed at site prior to surface

preparation and application of the Saudi Aramco coating and

painting system.




Page 52 of 54

b) Prepare the surface and apply the complete (primer and final

coatings) Saudi Aramco surface preparation, and coating and

painting system in the shop.

c) For solid Stainless Steel vessels, which are to be shipped via ocean

freight, shall be protected using a temporary protective system

compatible with stainless steel and suitable outdoor exposure.

19.3.2 Telltale holes in reinforcing pads shall be protected with wooden plugs

or packed with rust preventative grease.

19.3.3 Flanged connections and all other machined surfaces shall be protected

by a coating suitable for the metallurgy of the vessel and can be easily

removed in the field. Connections shall be fitted with steel or wood

cover, 3 mm thick and neoprene gaskets.

19.3.4 Covers shall be securely attached by a minimum of four bolts equally

spaced. For ocean shipment, flanged connections shall also be covered

with heavy-duty plastic bags securely taped to the nozzles.

19.3.5 Flanges with permanent blind flanges or covers shall be secured with

the gaskets and bolting specified for service.

20 Drawings, Calculations and Data

20.1 The Vessel Manufacturer shall Prepare drawings, calculations, and data in

accordance with NMR-7919-1, Nonmaterial Requirements. Calculations shall

include, but not limited to:

a. ASME Code Section VIII calculations.

b. Wind and earthquake calculations, as applicable.

c. Support calculations.

d. Calculations associated with lifting and erecting the vessel

e. Nozzle load analysis for local and gross effect, when required.

f. Design of internal and external attachments.

g. Design loads and load combinations.

20.2 Drawings and calculations that are approved by the Design Engineer shall not

relieve the Vessel Manufacturer from the responsibility to comply with the

Codes, and this specification.

20.3 Vessel manufacturer shall prepare drawings which indicate the ultrasonic

thickness of the vessel shell section, heads and nozzles. An adequate number of

http://standards/docs/Nonmaterial_Requirements/PDF/SA-7919-1.PD




Page 53 of 54

readings shall be taken to represent the actual thickness of the components.

20.4 All approved data sheets, drawings and forms are to be submitted to

EK&RD/Drawing Management Unit (DMU) for inclusion into Corporate

Drawings Management System.

Revision Summary

23 February 2011 Major revision. 22 May 2011 Editorial revision intended for clarifying some requirements of the document. 13 December 2011 Minor revision intended to reflect changes to some requirements, which have been already

included in the relevant SAES-D-001. 15 January 2012 Editorial revision intended for clarifying some requirements of the document.




Page 54 of 54

Table 1 – Nondestructive Examination Requirements

Weld Joint Category Radiography (RT) Ultrasonic (UT) Liquid Penetrant (LP) or Magnetic Particle (MP)

A and B Per Design Code Criteria (Spot or 100%) (1) & (3)

See Notes (2) & (3) 100%

C 100% (3) 100% (3) 100% (6)

D See Note (4) See Note (4) See Note (4)

Notes:

(1) 100% RT is required for vessels under any of the following services or design conditions:

Weld joints requiring full radiography per the applicable code.

Lethal services.

Hydrogen services.

Cyclic services.

Unfired steam boilers with design pressure exceeding 50 psi.

Thick wall.

(2) 100% conventional UT is required for only vessels under any of the services or design conditions per note 1 of this table.

(3) 100% UT, employing methods that generate permanent records may be used as a substitute for the combination of 100% RT and 100% conventional UT specified for vessels under common services and design conditions per notes 1 and 2 of this table. Such UT methods must be approved by Inspection Department prior to commencement of any work.

(4) Inspection for Category - D weld joint shall meet the following:

a) 100% RT and 100% Conventional UT for design conditions/ services Group I per paragraph 8.5.2 of this specification. Alternatively, 100% UT employing methods that generate permanent records can be used, where such methods must be approved by the Inspection Department prior to commencement of any work.

b) Following design details shall be used where RT is required for Category - D weld joint:

i. For Division 1 vessels: Figures UW-16.1: (f-1), (f-2), (f-3) or (f-4).

ii. For Division 2 vessels: Figures 4.2.13: (1), (2), (3), (4), (5) or (6).

c) Where RT cannot be utilized, due to only joint geometry, 100% UT shall be performed on the joint from an accessible side. If conventional UT method can not be utilized, other UT methods shall be used and must be approved by Inspection Department prior to commencement of any work.

d) Where RT and UT cannot be utilized, due to only joint geometry, following examination shall be performed:

i. For attachments without a reinforcing pad, the whole joint shall be either 100% magnetic particle (MP) or 100% liquid penetrant (LP) examined at the root pass, after each 6 mm depth of weld deposit and the final weld surface. Where PWHT is required, final surfaces of weld joints shall be examined for acceptance after final PWHT.

ii. For attachments with a reinforcing plate, similar examination as in (i) above shall be performed at the nozzle. 100% MT or 100% LP shall be also performed on the final surface of the fillet welds attaching the reinforcing pad to vessel and nozzle.

(5) Inspection requirements for connections attached to nozzles and manways per paragraph 8.5.2 shall be according to note 4 of this table.

(6) 100% MT or 100% LP shall be applied to the root pass and final surface of lap-welded Category - C weld joint.

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32-SAMSS-004 DATED JAN 15-2012

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