DNVGL-RU-HSLC-Pt4Ch6 Piping systems€¦ · 5.1 Flange connections ... 1.1.1 The rules in this...

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DNV GL AS

RULES FOR CLASSIFICATION

High speed and light craftEdition December 2015

Part 4 Systems and components

Chapter 6 Piping systems

FOREWORD

DNV GL rules for classification contain procedural and technical requirements related to obtainingand retaining a class certificate. The rules represent all requirements adopted by the Society asbasis for classification.

© DNV GL AS December 2015

Any comments may be sent by e-mail to [email protected]

If any person suffers loss or damage which is proved to have been caused by any negligent act or omission of DNV GL, then DNV GL shallpay compensation to such person for his proved direct loss or damage. However, the compensation shall not exceed an amount equal to tentimes the fee charged for the service in question, provided that the maximum compensation shall never exceed USD 2 million.

In this provision "DNV GL" shall mean DNV GL AS, its direct and indirect owners as well as all its affiliates, subsidiaries, directors, officers,employees, agents and any other acting on behalf of DNV GL.

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Rules for classification: High speed and light craft — DNVGL-RU-HSLC-Pt4Ch6. Edition December 2015 Page 3Piping systems

DNV GL AS

CURRENT – CHANGES

This is a new document.

The rules enter into force 1 July 2016.

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CONTENTS

Current – changes...................................................................................................... 3

Section 1 General....................................................................................................... 71 Classification...........................................................................................7

1.1 Application.......................................................................................... 72 Definitions.............................................................................................. 7

2.1 Terms................................................................................................. 73 Documentation........................................................................................7

3.1 Plans and particulars............................................................................ 74 Certification............................................................................................ 9

4.1 General...............................................................................................95 Signboards............................................................................................10

5.1 General............................................................................................. 10

Section 2 Materials...................................................................................................111 Piping Systems..................................................................................... 11

1.1 General............................................................................................. 111.2 Copper and copper alloys....................................................................111.3 Non-metallic materials........................................................................ 111.4 Aluminium......................................................................................... 12

Section 3 Design principles...................................................................................... 131 Arrangement.........................................................................................13

1.1 Piping systems...................................................................................131.2 Operation of valves............................................................................ 13

Section 4 Craft piping systems.................................................................................141 Bilge pumping, drainage, air, sounding and filling pipes.......................14

1.1 Bilge pumping and drainage systems....................................................141.2 Air, sounding and filling pipes.............................................................. 161.3 Scuppers and discharges.....................................................................161.4 Fittings on sides and bottom............................................................... 17

Section 5 Machinery piping systems and ventilation................................................ 181 General................................................................................................. 18

1.1 Tank arrangement for fuel oil or other flammable fluids........................... 181.2 Piping conveying fuel or other flammable fluids......................................19

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1.3 Lubricating oil arrangements................................................................191.4 Arrangements for heated fuel oil tanks and equipment for fuel oil treatment. 191.5 Arrangement for fuel oil with flashpoint below 43°C................................20

2 Other Systems...................................................................................... 212.1 Ballast systems.................................................................................. 212.2 Cooling systems................................................................................. 212.3 Starting systems................................................................................ 212.4 Exhaust systems................................................................................ 222.5 Engine air intake systems................................................................... 232.6 Machinery space ventilation................................................................. 232.7 Pneumatic equipment......................................................................... 23

Section 6 Pipes, pumps, valves, flexible hoses and detachable pipe connections.... 251 Pipes.....................................................................................................25

1.1 General............................................................................................. 251.2 Minimum wall thicknesses of metallic pipes............................................251.3 Plastic pipes...................................................................................... 26

2 Pumps...................................................................................................282.1 Relief valves...................................................................................... 282.2 Hydrostatic tests................................................................................ 282.3 Capacity tests.................................................................................... 28

3 Valves................................................................................................... 283.1 Valve design...................................................................................... 283.2 Hydrostatic tests................................................................................ 29

4 Flexible Hoses.......................................................................................294.1 General............................................................................................. 294.2 Installation........................................................................................ 29

5 Detachable pipe connections................................................................ 305.1 Flange connections............................................................................. 305.2 Pipe couplings other than flanges.........................................................305.3 Expansion joints and bellows............................................................... 30

Section 7 Manufacture, workmanship, inspection and testing.................................. 311 Joining of plastic pipes.........................................................................31

1.1 General............................................................................................. 312 Welding and brazing.............................................................................31

2.1 General............................................................................................. 313 Hydrostatic tests of piping................................................................... 31

3.1 Hydrostatic testing after assembly on board.......................................... 31

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4 Functional testing................................................................................. 324.1 General............................................................................................. 32

5 Non-destructive testing........................................................................ 325.1 General............................................................................................. 32

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SECTION 1 GENERAL

1 Classification

1.1 Application

1.1.1 The rules in this chapter apply to piping for the assignment of main class notation 1A LC and 1AHSLC.

1.1.2 Compliance with the rules is required for installations and equipment necessary for performing themain functions given in SHIP Pt.1 Ch.1 Sec.1.

1.1.3 The rules give system requirements and prescribe minimum requirements for materials, design,manufacture, inspection and testing.

1.1.4 For the application of these rules, wherever the term Administration is quoted, this shall be read as theSociety.

2 Definitions

2.1 Terms

2.1.1 Piping is defined to include the following components:

— pipes— flanges with gaskets and bolts and other pipe connections— expansion elements— valves, including hydraulic and pneumatic actuators, and fittings— hangers and supports— flexible hoses— pump housings.

2.1.2 A piping system is defined to include piping, as well as components in direct connection to thepiping such as pumps, heatexchangers, evaporators, independent tanks, etc. with the exception of maincomponents such as steam and gas turbines, diesel engines, reduction gears and boilers.For components which are subject to internal pressure and are not included in the piping, the designrequirements in SHIP Pt.4 Ch.7 apply.

3 Documentation

3.1 Plans and particulars

3.1.1 Documentation shall be submitted as required by Table 1.

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Table 1 Documentation requirements

Object Documentation type Additional description Info

Machinery Z030 – Arrangement plan Layout of machinery components such as engines,fans, heat exchangers, generators, switchboards,pumps, purifiers, filters etc. but excluding pipes,valves and accessories.

FI

Bilge handling systems Including bilge pumping and drainage systems. AP

Ballast system AP

Air pipes Including filling pipes AP

Overflow system AP

Sounding systems AP

Scuppers Including dischargers AP

Sea water inlets andoutlets

Including fittings on sides and bottom

Fuel oil system Including:

— tank arrangement for fuel and other flammablefluids.

AP

Lubrication oil system AP

Sea water system Cooling system AP

Fresh water system Cooling system AP

Starting system AP

Exhaust gas systems AP

Anchor windlasseshydraulicsystem AP

Valve control hydraulicsystem AP

Internal watertightdoors / ramps hydraulicsystem

S010 – Piping diagram (PD)

AP

Control and monitoring I200 – Control and monitoringsystem documentation

Applicable for valves and pumps in system listed inthis table, if arranged

Ventilation systems S012 – Ducting diagram (DD) Machinery space ventilation AP

AP = For approval; FI = For informationACO = As carried out; L = Local handling; R = On request; TA = Covered by type approval; VS = Vessel specific

For general requirements for documentation, including definition of the info codes, see SHIP Pt.1 Ch.3 Sec.2.For a full definition of the documentation types, see SHIP Pt.1 Ch.3 Sec.3.

3.1.2 Analyses of reliability and availability shall be submitted upon request when considered necessary bythe Society.These analyses shall include information on possible numerical background material.

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3.1.3 Documentation for the control and monitoring system for valves and pumps for systems listed in Table1 shall be submitted for approval, if arranged. For requirements , see SHIP Pt.4 Ch.9.

4 Certification

4.1 GeneralRequired certificates are given in Table 2.

Table 2 Certification requirements

Objective Certificatetype

Issued by Certificationstandard* Additional description

Pumps PC Society

— sea-water cooling pumps forpropulsion drivers

— fresh-water cooling pumps forpropulsion drivers

— fuel oil service pumps— fuel injection valve cooling pumps— lubricating oil pumps for main

engine and reduction gear— bilge pumps— ballast pumps— fire pumps and emergency fire

pumps— other pumps considered necessary

for performing of the main functionslisted in SHIP Pt.1 Ch.1 Sec.1.

Plastic pipes TA Society If serving ship’s main functions (seeSec.2 [1.3])

Flexible hoses TA Society Hoses and couplings, see Sec.6 [4.1]

Detachable pipeconnection other thanflange

TA Society

Including screwed pipe coupling, bite/compression type, expansion jointsand bellows, See Sec.6 [5.2] and Sec.6[5.3]

Sea valves TR Manufacturer Hydrostatic testing in the presence ofthe surveyor. See Sec.6 [3.2.3]

*Unless otherwise specified the certification standard is the rules.

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5 Signboards

5.1 GeneralSignboards provide information or certain conditions to be complied with for the safe handling of machinerycomponents and systems.Some signboards are required by the rules, others may be required by the Society in each particular case.In Sec.1 of each chapter a summary of the signboards required by the rules in that chapter is introduced.

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SECTION 2 MATERIALS

1 Piping Systems

1.1 GeneralThe materials to be used in piping systems shall be suitable for the medium and service for which the systemis intended. Unless specifically mentioned all metallic materials with melting point above 900°C may be used.

Guidance note:Stainless steel is generally not considered suitable for use in seawater systems.

---e-n-d---of---g-u-i-d-a-n-c-e---n-o-t-e---

1.2 Copper and copper alloys

1.2.1 Copper and copper alloys are in general not to be used for media having temperature above thefollowing limits:

— copper and aluminium brass: 200°C— copper nickel: 300°C.

Special bronze suitable for high temperature service may be used for media having temperature up to 260°C.

1.2.2 Pipes for starting air are not to be of copper or copper alloys when the outer diameter exceeds 44.5mm.

1.3 Non-metallic materials

1.3.1 Pipes made from non-metallic materials may be used in piping systems with the following exceptions:

— systems conveying flammable fluids— systems with design pressure above 16 bar— fire extinguishing systems— sounding and air pipes to flammable fluid tanks— Bilge system in fire hazardous area unless fire endurance tested.

1.3.2 For crafts which are required to comply with HSC code, pipes made from non-metallic material shallbe fire endurance tested if they are used in systems where failure could result in flooding of watertightcompartments due to fire.

Guidance note:Refer also to Ch.1 Sec.1 . Systems where failure could result in flooding of watertight compartment due to fire include, but arenot limited to

— Sea water cooling system

— Ballast system in fire hazard area

— Scupper in fire hazardous area

— Bilge system in fire hazardous area

— Sanitary discharge

Fire hazardous area refers to definition in Ch.1 Sec.1.


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1.3.3 Pipes made from non-metallic materials, shall be type approved by the Society for its intended servicefor main function piping systems (as listed in Sec.1 Table 2), and be of a recognised standard for other non-essential services.

1.4 AluminiumPipes made from aluminium or aluminium alloy may be used in piping system with the following exception

— System conveying flammable fluids— System with design pressure above 16bar— Fire extinguishing system— Bilge system within fire hazardous area

In addition, air, sounding and filling pipes for aluminium oil tanks may be made from the same material,provided these pipes are located outside fire hazard areas.

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SECTION 3 DESIGN PRINCIPLES

1 Arrangement

1.1 Piping systems

1.1.1 Piping systems are normally to be made of rigid pipes. The use of flexible pipes of approved typesuitable for their intended use may be accepted in lieu of rigid piping upon special consideration. Pipes andfittings shall be supported in such a way that their weight is not taken by connected machinery or that heavyvalves and fittings do not cause large additional stresses in adjacent pipes.

1.1.2 Axial forces due to internal pressure, change in direction or cross-sectional area and movement of thecraft shall be taken into consideration when mounting the piping system.

1.1.3 The support of the piping system shall be such that detrimental vibrations will not arise in the system.

1.1.4 Metallic pipes shall be connected by welding or brazing in accordance with the requirements in Sec.7[2] or by detachable connections of approved type.

1.1.5 Plastic pipes shall be connected by an approved method e.g. welding, gluing or cementing, or byapproved detachable connections.

1.1.6 Installation of pipes for water or oil, behind or above electric switchboards shall be avoided as far aspossible. If this is impracticable, all detachable pipe joints and valves shall be at a safe distance from theswitchboard or well shielded from it.

1.1.7 Water pipes and air and sounding pipes through freezing chambers shall be avoided.

1.2 Operation of valves

1.2.1 Sea suction and discharge valves, bilge valves and valves on the fuel oil and lubricating oil tanks whichare situated higher than the double bottom tanks, shall be arranged for local mechanical manual operation.The change over to manual operation from possible remote control arrangement shall be simple to execute.

1.2.2 For remotely controlled valves failure in power supply is not to cause:

— opening of closed valves— closing of open valves on fuel oil tanks and in cooling water system for propulsion and power generating

machinery.

1.2.3 Remotely controlled valves shall be provided with indications for open and closed valve positions at thecontrol station.In cases where possibility of direct manual operation is required in addition to the remote control, means ofobserving the valve position at the valve location shall be provided.

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SECTION 4 CRAFT PIPING SYSTEMS

1 Bilge pumping, drainage, air, sounding and filling pipes

1.1 Bilge pumping and drainage systems

1.1.1 Arrangements shall be made for draining any watertight compartment other than the compartmentsintended for permanent storage of liquid. Where, in relation to particular compartments, drainage is notconsidered necessary, drainage arrangements may be omitted, but it shall be demonstrated that the safetyof the craft will not be impaired.(HSC Code 10.3.1)

1.1.2 Bilge pumping arrangements shall be provided to allow every watertight compartment other than thoseintended for permanent storage of liquid to be drained. The capacity or position of any such compartmentshall be such that flooding thereof could not affect the safety of the craft.(HSC Code 10.3.2)

1.1.3 The bilge pumping system shall be capable of operation under all possible values of list and trim afterthe craft has sustained the postulated damage in 2.6.5 to 2.6.8 of HSC code. The bilge pumping system shallbe so designed as to prevent water flowing from one compartment to another. All distribution boxes andmanually operated valves in connection with the bilge pumping arrangements shall be in positions which areaccessible under ordinary circumstances.For craft where compliance with the HSC Code is required, the necessary valves for controlling the bilgesuctions shall be capable of being operated from above the datum.

1.1.4 For bilge pumping system where bilge main is provided, at least 2 power operated self-primingbilge pumps shall be provided. One of the bilge pumps may be a bilge ejector if there is a separate pumpdelivering sufficient water for operating the ejector.The power-operated self-priming bilge pumps may be used for other duties such as fire fighting or generalservice but not for pumping fuel or other flammable liquids.(HSC Code 10.3.4)

1.1.5 On multi-hull craft where bilge main is provided, each hull should be provided with at least 2 bilgepumps, unless a bilge pump in one hull is capable of pumping bilge in the other hull. If the arrangement iswith one pump in one hull to drain the other hull, due attention shall be paid to the suction capability of bilgesystem. At least one pump in each hull shall be an independent power pump.

1.1.6 Each power bilge pump shall be capable of pumping water through the required bilge pipe at a speedof not less than 2 m/s.(HSC Code 10.3.5)

1.1.7 The diameter (d) of the bilge main shall be calculated according to the following formula, exceptthat the actual internal diameter of the bilge main may be rounded off to the nearest size of a recognizedstandard:

d = 25 + 1.68 (L (B + D)) 0.5

where:

d = the internal diameter of the bilge main (mm);L = the length of the craft (m) as defined in Pt.3 Ch.1 Sec.1;

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B = for monohull craft, the breadth of the craft in m as defined in Pt.3 Ch.1 Sec.1) and, for multihullcraft, the breadth of a hull at or below the design waterline (m); and

D = the moulded depth of the craft to the datum (m).

(HSC Code 10.3.6)Guidance note:Reference is given to Ch.1 of HSC code regarding the definition of the word datum.


1.1.8 Internal diameters of suction branches shall meet the requirements of the Administration but shall notbe less than 25 mm. Suction branches shall be fitted with effective strainers.(HSC Code 10.3.7)

1.1.9 An emergency bilge suction shall be provided for each machinery space containing a propulsion primemover. This suction shall be led to the largest available power pump other than a bilge pump, propulsionpump or oil pump.(HSC Code 10.3.8)

Emergency bilge suction shall be provided for craft with a common bilge pumping systems according to[1.1.7] and for craft with individual bilge pumps according to [1.1.15]

1.1.10 The spindles of the sea inlet valves shall extend well above the machinery space floor plates.(HSC Code 10.3.9)

1.1.11 All bilge suction piping up to the connection to the pumps shall be independent of other piping.(HSC Code 10.3.10)

1.1.12 Spaces situated above the water level in the worst anticipated damage conditions may be draineddirectly overboard through scuppers fitted with non-return valves.(HSC Code 10.3.11)

1.1.13 Any unattended space for which bilge pumping arrangements are required shall be provided with abilge alarm.(HSC Code 10.3.12)

1.1.14 For craft with individual bilge pumps, the total capacity Q of the bilge pumps for each hull shall not beless than 2.4 times the capacity of the pump defined in 10.3.5 ([1.1.6]) and 10.3.6 ([1.1.7]).(HSC Code 10.3.13)

1.1.15 In bilge pumping arrangements where a bilge main is not provided, then, with the exception offore peak compartment which is located forward of public spaces and crew accommodation, at least onefixed submersible pump shall be provided for each space. In addition, at least one portable pump shall beprovided supplied from the emergency supply, if electric, for use on individual spaces. The capacity of eachsubmersible pump Qn shall not be less than:

Qn = Q / (N-1) tonne/h with a minimum of 8 tonnes/h

where:

N = number of submersible pumpsQ = total capacity as defined in 10.3.13 of HSC Code ([1.1.14]).

The portable pump shall have a capacity not less than 8m3/h.

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1.1.16 Non-return valves shall be fitted in the following components:

1) bilge valve distribution manifolds;2) bilge suction hose connections where fitted directly to the pump or to the main bilge suction pipe; and3) direct bilge suction pipes and bilge pump connections to main bilge suction pipe.

(HSC Code 10.3.15)

1.1.17 Two non-return valves in series shall be arranged between sea or ballast system and bilge suctions incompartments. This is applicable also for bilge pump discharges located above the waterline. For emergencybilge suctions in machinery spaces, one non-return valve will be acceptable.

1.2 Air, sounding and filling pipes

1.2.1 All compartments and tanks arranged with filling and/or drainage arrangement shall have air pipe andmeans for ascertaining the level of liquid.

1.2.2 All tanks containing flammable liquids or which can be pumped up or filled from the sea shall have airpipe extending above the weather deck.

1.2.3 Air pipes from fuel oil and lubricating oil systems shall be carried up to a position where water cannotenter and so arranged that vapour or overflow cannot be ignited.Air pipes from lubricating oil storage tanks may terminate in the machinery space, provided that the openends are so located that issuing oil cannot come into contact with electronic equipment or heated surface.

1.2.4 All air pipes outlets shall have approved automatic means preventing ingress of water and sucharrangement shall be so that the tanks are not exposed to vacuum or pressure exceeding the designpressure or vacuum.

1.2.5 All tanks containing flammable liquids or which can be pumped up or filled from the sea shall havesounding pipe carried up to the open air fitted with screw cap or equivalent. Other approved level indicator orremote sounding arrangement may replace sounding pipe.

1.2.6 Filling pipes to tanks containing flammable liquids shall terminate on the weather deck and shall be soarranged that possible spill cannot escape to the inside of the vessel, but will be collected inside a suitablyarranged coaming.

1.2.7 All filling pipes to fuel oil and lubricating oil tanks shall have screw caps, plugs or similar arrangementpreventing water from entering such tanks.

1.2.8 Overflow pipes shall have sectional area not less than 125% of the filling pipes. The same requirementapplies to air pipes on tanks not fitted with overflow pipes.

1.3 Scuppers and discharges

1.3.1 A sufficient number of scuppers, arranged to provide effective drainage, shall be fitted to all decks.

1.3.2 Scuppers on weather portions of decks and scuppers leading from superstructures or deckhouses notprovided with closing appliances, are usually to be led overboard.

1.3.3 Scuppers led through the deck or shell shall comply with requirements to material and thickness asgiven in [1.4.3].

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1.3.4 Scupper pipes shall be well stayed to prevent any vibrations; however, sufficient possibility forexpansion of the pipes to be provided when necessary.

1.3.5 Scuppers from spaces below the freeboard deck or spaces within closed superstructures may be led tobilges.

1.3.6 Scuppers leading overboard from spaces mentioned in [1.3.5] shall comply with the requirementsgiven in [1.3.7] for discharges. Scuppers from exposed superstructure deck, led through the ship’s sides andnot having closeable valves, shall have strength as required in [1.4.3].

1.3.7 Discharges led through the shell either from spaces below the datum or from within superstructuresand deckhouses fitted above the datum shall be fitted with efficient and accessible means for preventingwater from passing inboard.Normally each separate discharge shall have one automatic non-return valve with a positive means of closingit from a position above the datum. Where, however, the vertical distance from the design waterline to theinboard end of the discharge pipe exceeds 0.01 L, the discharge may have two automatic non-return valveswithout positive means of closing, provided that the inboard valve is always accessible for examination underservice conditions. Where that vertical distance exceeds 0.02 L, a single automatic non-return valve withoutpositive means of closing may be accepted. The means for operating the positive action valve shall be readilyaccessible and provided with an indicator showing whether the valve is open or closed.

1.4 Fittings on sides and bottom

1.4.1 All sea inlets and discharges shall have easily operable valves of an approved type connected to theside or bottom of the craft by a substantial flange connection or equivalent. The valves shall be of lug type,so that piping inboard of the valves may be disconnected without interfering with the watertight integrity ofthe shell.

1.4.2 The choice of material combination, dimensioning and corrosion protection of the sea inlet anddischarge valves connection to the sides and bottom of the craft shall be so arranged that flooding as areason of damage of such fitting is avoided. Such valves are not to be made from grey cast iron.

1.4.3 For steel or aluminium craft, the pipe between hull plating and closeable or non-return valve shall havethe same thickness as the surrounding hull structure.For non-metallic craft, the thickness and diameter of piping between hull plating and closeable or non-returnvalve shall be chosen so as to achieve equivalent strength as the surrounding hull structure.Due regard to be taken to the corrosion resistance of the piping material.

1.4.4 All sea inlet valves and outlet valves fitted below the waterline shall be arranged for direct mechanicalclosing with the manoeuvring handle situated easily accessible and visible above the waterline. Valve positionindicator shall be visible at the manoeuvring stand.

1.4.5 For craft where compliance with the HSC Code is required. In unmanned machinery spaces, main andauxiliary sea inlet and discharge controls in connection with the operation of machinery shall either:

1) be located at least 50% of the significant wave height corresponding to the worst intended conditionsabove the deepest flooded waterline following damage specified in 2.6.6 to 2.6.10 of HSC code; or

2) be operable from the operating compartment.

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SECTION 5 MACHINERY PIPING SYSTEMS AND VENTILATION

1 General

1.1 Tank arrangement for fuel oil or other flammable fluids

1.1.1 The requirements in this section apply to craft using fuel oil or other flammable fluids with a flash pointnot lower than 43°C. However, fuel oil with a lower flash point but not lower than 35°C may be used providedsuitable precautions are taken against the risk of fire and explosion as described in [1.5].

1.1.2 Fuel oil tanks for emergency diesel engines shall be located on or above the weather deck andpreferably in the same compartment as the emergency diesel engine.

1.1.3 Fuel oil tanks or tanks containing other flammable fluids, are not to be located in or adjacent to areasof major fire hazard, except as permitted in [1.1.4].

Guidance note:The term areas of major fire hazard areas in [1.1.3] and [1.1.4] refers to HSC code.


1.1.4 Tanks as mentioned in [1.1.3] may be located in areas of major fire hazard, provided the followingconditions are met:

— the tank is made from steel or other equivalent material— the tank content has a flash point not lower than 60°C— the tank is a daily service tank or a double bottom tank.

1.1.5 Tanks containing fuel oil or other flammable fluids shall be designed to withstand the maximum headto which they may be subjected in service taking into account the dynamic forces encountered.

1.1.6 Tanks for fuel oil or other flammable fluids not forming part of the craft’s structure shall be securelyfastened and shall be arranged so as to be readily inspected or movable for inspection.

1.1.7 Tanks as mentioned in [1.1.6] shall be so installed as to provide a free circulation of air around thetanks.

1.1.8 All tanks containing fuel oil or other flammable fluids shall be separated from passenger, crew andbaggage compartments by cofferdams or equivalent.

1.1.9 Tanks containing fuel oil or other flammable fluids having connections below the highest tank liquidlevel shall have spill tray so arranged that any spill can be collected and led to a collecting tank or equivalentin order to prevent leakage or spillage to the bilge from detachable piping connections.

1.1.10 Level gauges of approved type may be used in place of sounding pipes. No tubular gauge glassesshall be fitted to tanks containing fuel oil or other flammable fluids. Level gauge with flat glasses may bepermitted with self-closing valves fitted between the gauges and oil tanks.However, level gauge in passenger craft shall not penetrate below the top of the tank and their failure oroverfilling of the tank shall not permit release of fuel oil or other flammable fluids.

1.1.11 Small test-cocks may be fitted to tanks containing fuel oil or other flammable fluids, provided thecocks are of self-closing type and are located above drip trays.

1.1.12 Provision shall be made to prevent over-pressure in tanks containing fuel oil or other flammablefluids.

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1.2 Piping conveying fuel or other flammable fluids

1.2.1 Piping conveying fuel oil or other flammable fluids shall be adequately screened or otherwise protectedto avoid oil leakage onto hot surfaces, electrical equipment, or other sources of ignition.As far as practicable, all parts of the piping system shall be so located that defects and leakages can readilybe observed. The number of detachable pipe connections shall be kept to a minimum.

Guidance note:See MSC/Circ.647, "Guidelines to Minimize Leakages from Flammable Liquid Systems for Improving Reliability and Reducing Riskof Fire".


1.2.2 Piping conveying fuel oil or other flammable fluids shall be accessible, protected from mechanicaldamage, be effectively secured against excessive movements and vibration. Flexible pipes shall have suitableconnections, be resistant to salt, water, oil and vibration, be visible, easily accessible and are not to penetratewatertight bulkheads. The number of flexible pipes shall be kept a minimum.

1.2.3 Filling, air, overflow and drain lines to or from tanks containing fuel oil or other flammable fluids shallbe of adequate size and terminate in a manner that will not constitute a hazard.

1.2.4 Piping conveying fuel oil or other flammable fluids is not to be carried through passenger, crew andbaggage compartments.

1.2.5 Inlet and outlet pipes of tanks containing fuel oil or other flammable fluids shall be fitted with shut-offvalves located on the tank itself if the pipes are connected to the tank below the tank top (or below the outletof the overflow pipe if fitted).

1.2.6 All valves mentioned in [1.2.5] and which are open during normal operation shall be arranged for quickacting shut-off. The operation shall be carried out from a position outside the space concerned.For filling valves, non-return valves may be accepted as an alternative to remote operation.Valves on tanks below 0.5 m3 need not be arranged for remote shut-off.

1.2.7 The use of hydraulic or pneumatic systems for keeping quick-acting shut-off valves in open position willnot be accepted.

1.3 Lubricating oil arrangementsThe arrangements for the storage, distribution and utilisation of lubrication oil are in general to comply withthe provisions in [1.1] and [1.2], except that:

— sight-flow glasses may be permitted, provided they are shown by test to have a suitable degree of fireresistance

— short sounding pipes may be permitted in machinery spaces, provided the pipes are fitted withappropriate means of closure and terminate in safe distance from ignition hazards.

1.4 Arrangements for heated fuel oil tanks and equipment for fuel oiltreatment

1.4.1 Where daily service fuel oil tanks or settling tanks are fitted with heating arrangements, a hightemperature alarm shall be provided if the flashpoint of the oil can be reached due to failure of thethermostatic control.

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1.4.2 Equipment that treats flammable liquids automatically, such as fuel oil purifiers which, wheneverpracticable shall be installed in a special space reserved for purifiers and their heaters, shall havearrangements to prevent overflow spillage.

1.5 Arrangement for fuel oil with flashpoint below 43°C

1.5.1 Fuel with a flashpoint below 35°C shall not be used. In every craft in which fuel with a flashpoint below43°C is used, the arrangements for the storage, distribution and utilization of the fuel shall be such that,having regard to the hazard of fire and explosion which the use of such fuel may entail, the safety of thecraft and of persons on board is preserved. The arrangements shall comply, in addition to the requirementsof 7.5.1 to 7.5.5 of the HSC Code, with the following provisions:

1) tanks for the storage of such fuel shall be located outside any machinery space and at a distance of notless than 760 mm inboard from the shell side and bottom plating and from decks and bulkheads;

2) arrangements shall be made to prevent over-pressure in any fuel tank or in any part of the oil fuelsystem, including the filling pipes. Any relief valves and air or overflow pipes shall discharge to a positionwhich, in the opinion of the Administration, is safe;

3) the spaces in which fuel tanks are located shall be mechanically ventilated using exhaust fans providingnot less than six air changes per hour. The fans shall be such as to avoid the possibility of ignition offlammable gas-air mixtures. Suitable wire mesh guards shall be fitted over inlet and outlet ventilationopenings. The outlets for such exhausts shall be discharged to a position which, in the opinion of theAdministration, is safe. ’No Smoking’ signs shall be posted at the entrances to such spaces;

4) earthed electrical distribution systems shall not be used, with the exception of earthed intrinsically safecircuits;

5) suitable certified safe type electrical equipment shall be used in all spaces where fuel leakages couldoccur, including the ventilation system. Only electrical equipment and fittings essential for operationalpurposes shall be fitted in such spaces;

Guidance note:See Recommendations published by the International Electrotechnical Commission and, in particular, publication 60092 -Electrical Installations in Ships.


6) fixed vapour-detection system shall be installed in each space through which fuel lines pass, with alarmsprovided at the continuously manned control station;

7) every fuel tank shall, where necessary, be provided with ’savealls’ or gutters which would catch any fuelwhich may leak from such tank;

8) safe and efficient means of ascertaining the amount of fuel contained in any tank shall be provided.Sounding pipes shall not terminate in any space where the risk of ignition of spillage from the soundingpipe might arise. In particular, they shall not terminate in passenger or crew spaces. The use of gaugeglasses is prohibited. Other means of ascertaining the amount of fuel contained in any tank may bepermitted if such means do not require penetration below the top of the tank, and providing their failureor overfilling of the tank will not permit the release of fuel;

9) during bunkering operations no passenger shall be on board the craft or in the vicinity of the bunkeringstation, and adequate ’No Smoking’ and ’No Naked Lights’ signs shall be posted. Vessel-to-shore fuelconnections shall be of closed type and suitably earthed during bunkering operations;

10) the provision of fire-detection and extinguishing systems in spaces where non-integral fuel tanks arelocated shall be in accordance with paragraphs 7.7.1 to 7.7.4 of the HSC Code(, and

11) refuelling of the craft shall be done at the approved refuelling facilities, detailed in the route operationalmanual, at which the following fire appliances are provided:

a) suitable foam applicator system consisting of monitors and foam making branch pipes capable ofdelivering foam solution at a rate of not less than 500 l/min for not less than 10 min;

b) dry powder extinguishers of total capacity not less than 50 kg; andc) carbon dioxide extinguishers of total capacity not less than 16 kg.

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(HSC Code 7.5.6)

1.5.2 Air pipes from tanks containing fuel oil with flash point less below 43°C shall be fitted with flamearresters.

Guidance note:See MSC/Circ.677 "Revised Standards for the Design, Testing and Locating of Devices to Prevent the Passage of Flame into CargoTanks".


2 Other Systems

2.1 Ballast systems

2.1.1 Water ballast shall not in general be carried in tanks intended for oil fuel. In craft in which it is notpracticable to avoid putting water in oil fuel tanks, oily-water separating equipment shall be fitted, orother alternative means such as discharge to shore facilities shall be provided for disposing of the oily-water ballast. The provisions of this paragraph are without prejudice to the provisions of the InternationalConvention for the Prevention of Pollution from Ships in force.(HSC Code 10.4.1)

2.1.2 Where a fuel-transfer system is used for ballast purposes, the system shall be isolated from anywater ballast system and meet the requirements for fuel systems and the International Convention for thePrevention of Pollution from Ships in force.(HSC Code 10.4.2)

2.2 Cooling systemsThe cooling arrangements provided shall be adequate to maintain all lubricating and hydraulic fluidtemperatures within manufacturers’ recommended limits during all operations for which the craft shall becertificated.(HSC Code 10.5)

2.3 Starting systems

2.3.1 Propulsion and generator engines shall be equipped with starting arrangement of sufficient capacitywhich can be easily operated without external aid.

2.3.2 Starting arrangements shall have total capacity for starting the propulsion engine at least 6 times, andeach generator engine at least 3 times without recharging. For multi-engine propulsion plants, capacity of thesystem shall be sufficient for 3 starts per engine. However, the total capacity is not to be less than 12 startsand need not exceed 18 starts.

2.3.3 Equipment for recharging of the engine starting power capacities as required in [2.3.2] shall beavailable onboard the craft.In the case of pneumatic starting arrangements such recharging shall be possible within one hour. For othertypes of starting arrangements required recharging time will be considered case by case.

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2.4 Exhaust systems

2.4.1 All engines exhaust systems shall be adequate to assure the correct functioning of the machinery andthat safe operation of the craft is not put at risk.(HSC Code 10.8.1)

2.4.2 Exhaust systems shall be so arranged as to minimize the intake of exhaust gases into manned spaces,air-conditioning systems, and engine intakes. Exhaust systems shall not discharge into air-cushion intakes.(HSC Code 10.8.2)

2.4.3 Pipes through which exhaust gases are discharged through the hull in the vicinity of the waterlineshall be fitted with erosion-/corrosion-resistant shut-off flaps or other devices on the shell or pipe end andacceptable arrangements made to prevent water flooding the space or entering the engine exhaust manifold.(HSC Code 10.8.3)

Guidance note:Other devices than a shut-off flap may be a gate valve that can be closed, or a loop extending sufficiently high above the waterline.


2.4.4 Gas turbine engine exhausts shall be arranged so that hot exhaust gases are directed away from areasto which personnel have access, either on board the craft or in the vicinity of the craft when berthed.(HSC Code 10.8.4)

2.4.5 Drainage shall be arranged where needed.

2.4.6 Above S.W.L. the wall thickness of exhaust piping of stainless steel is not to be less than 2.0 mm.

Table 1 Stainless steel pipe thickness

Exhaust pipe diameter (mm) Minimum wall thickness (mm)

D < 76.176.1 < D < 108.0

108.0 < D < 159.0

159.0 < D < 267.0

267.0 < D < 457.0

457 < D

2.02.25

2.5

3.0

4.0

4.5

For other material than stainless steel the wall thickness will be especially considered.

2.4.7 Materials used below S.W.L and in the seawater cooled part of the exhaust pipe shall be of a suitabletype in sea water services taking into account possible localised corrosion.

2.4.8 Exhaust pipes led through bulkheads or hull shall be thermally insulated from the bulkhead and hull.Guidance note:Maximum continuous operating temperature in sandwich construction is 80°C.The susceptibility to exfoliation corrosion and stress corrosion cracking of 5000 series aluminium alloys containing more than about3% magnesium may increase when subject to long term exposure to temperatures exceeding 65°C.


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2.4.9 Exhaust pipes with expansion bellows shall be adequately adjusted, aligned and clamped. Sufficientdistance to other structures are in general to be provided, and in particular when this is of GRP and oraluminium.

2.4.10 Exhaust pipes, bellows and flanges shall be insulated.

2.4.11 Aluminium alloys should not be subject to long term exposure to temperatures exceeding 150°C dueto reduced mechanical properties.

2.5 Engine air intake systems

2.5.1 Arrangements shall provide sufficient air to the engine and shall give adequate protection againstdamage, as distinct from deterioration, due to ingress of foreign matter.(HSC Code 10.6)

2.5.2 Air intakes shall be positioned or provided with equipment to reduce the salt spray to the engines.

2.6 Machinery space ventilation

2.6.1 Ventilation systemsMachinery spaces shall be adequately ventilated so as to ensure that when machinery therein is operatingat full power in all weather conditions, including heavy weather, an adequate supply of air is maintainedto the spaces for the safety and comfort of personnel and the operation of the machinery. Auxiliarymachinery spaces shall be adequately ventilated appropriate for the purpose of those spaces. The ventilationarrangements shall be adequate to ensure that the safe operation of the craft is not put at risk.(HSC Code 10.7)

2.6.2 A mechanical ventilation system with suitable weather deck inlets and outlets including dampers shallbe provided for the machinery space.

2.6.3 Calculated air quantity required shall be based on the sum of the air demanded for diesel engines andboilers as well as the requirements for exhaustion of heat emitted from diesel engines, electrical equipment,boilers, exhaust pipes and tanks etc. However, in no case is air supply to be less than total sum of neededcombustion air plus 50%.

2.6.4 The air ventilation system shall be designed so as to keep a slight positive air pressure in themachinery space while operating at normal condition.

2.6.5 The temperature rise (maximum difference between exhaust and supply air) is normally not to exceed10°C assuming maximum ambient air temperature.

2.6.6 The air system shall be distributed and balanced in such way as to provide an atmosphere which isagreeable to the personnel, machinery and equipment throughout the space.

2.6.7 Air is not to discharge directly on insulated piping or electrical equipment nor should it be necessarythat air be directed at any equipment in order for it to function properly.

2.7 Pneumatic equipment

2.7.1 Components requiring extremely clean air are not to be used. Extremely small openings in airpassages shall be avoided.

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2.7.2 Main pipes shall be inclined relative to the horizontal, and drainage shall be arranged.

2.7.3 For air supply the redundancy requirement applies for compressors, pressure reduction units, filtersand air treatment units (lubricator or oil mist injector and de-humidifier).

2.7.4 Air to instrumentation equipment shall be free from oil, moisture and other contamination.Condensation is not to occur at relevant pressures and temperatures. For air flowing in pipes which arelocated entirely inside the machinery space and accommodation, the dew point shall be more than 10°Cbelow ambient temperature, but need normally not be lower than 5°C. The dew point of air flowing in pipeson open deck shall be below -25°C.

2.7.5 Reduction valves and filters shall be duplicated when serving more than one function (e.g. more thanone control loop).

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SECTION 6 PIPES, PUMPS, VALVES, FLEXIBLE HOSES ANDDETACHABLE PIPE CONNECTIONS

1 Pipes

1.1 General

1.1.1 The wall thicknesses of pipes shall comply with the requirements in this section.

1.1.2 For special applications and in cases where the pipes may be subject to excessive external loads or areinaccessible during service, greater wall thicknesses than given in the following may be required.

1.2 Minimum wall thicknesses of metallic pipes

1.2.1 The nominal wall thickness is generally not to be less than given in Table 1 for pipes of copper andcopper alloys and in Table 2 for steel pipes and aluminium pipes.

Table 1 Minimum nominal wall thickness for pipes of copper and copper alloys, titanium andstainless steel

Minimum nominal wallthickness (mm) 1)

External pipe diameter D(mm)

CopperCopper alloy and

stainless steel

D ≤ 10 1 0.8

10 < D ≤ 20 1.2 1

20 < D ≤ 44.5 1.5 1.2

44.5 < D ≤ 76.1 2 1.5

76.1 < D ≤ 108 2.5 2

108 < D ≤ 159 3 2.5

159 < D ≤ 267 3.5 3

267 < D ≤ 457 4 3.5

470 4 3.5

508 4.5 4

1) The wall thickness of pipes within ballast tanks in systems for remote control of valves is not to be less than: 3 mmfor Al-Brass, 2 mm for Cu-Ni and stainless steel.

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Table 2 Minimum nominal wall thickness for steel pipes and aluminium pipes

External diameter D (mm)Minimum nominal wall thickness 1)2)

(mm)

10.2–1213.5–17.2

20

1.61.8

2

21.3–2526.9–33.7

38–44.5

22

2

48.351–63.5

70

2.32.3

2.6

76.1–82.588.9–108

114.3–127

2.62.9

3.2

133–139.7152.4–168.3

177.8

3.64

4.5

1) For pipes efficiently protected against corrosion, the thickness may be reduced by 20% of the required wallthickness, but not more than 1 mm.

2) For threaded pipes, where allowed, the minimum wall thickness shall be measured at the bottom of the thread.

1.2.2 The outer diameters and wall thicknesses given in the tables are in accordance with ISO-standards. Forpipes covered by other standards thicknesses slightly less may be accepted.

1.3 Plastic pipes

1.3.1 Minimum wall thicknesses and acceptable internal pressure of plastic pipes are determined by longterm testing of hydraulic pressure strength according to an approved specification.

1.3.2 Evaluation of vacuum and external pressure resistance is necessary for plastic piping. Due to lowelasticity modulus the buckling stability may be critical in pipe systems where vacuum or external pressuresshall be expected.

1.3.3 Temperature limits and pressure reductions are indicated in Table 3 and Table 4. The limits may beextended on basis of acceptable documentation from the pipe manufacturer. The permissible temperaturesare stated for long term service. Short periods of marginally higher temperatures may be accepted by case tocase considerations.

1.3.4 The tables are related to water service only. Use for other media shall be considered case by case.

1.3.5 If thermoplastic pipes shall be installed in external areas, the pipes shall either be particularlyapproved for external use or be protected against ultraviolet radiation.

1.3.6 Plastic pipes are normally made of electrically insulating materials and are as such not acceptable forservice in gas hazardous areas. Special qualities can be permitted if they are documented to be electricallyconductive (antistatic) according to an approved specification.

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1.3.7 The need for expansion elements must be specially considered with respect to the large thermalexpansion coefficient of the plastic materials.

1.3.8 Glass fibre reinforced epoxy and polyester pipes are considerably more exposed to damage fromimpact and local overloading than steel pipes. This must be duly taken into consideration by handling,installation and inspection.

Table 3 Thermoplastic pipes. Permissible pressures and temperature limits

Permissible working pressure(bar)Material

Nominalpressure 1)

(bar) -20 to 0°C 30°C 40°C 50°C 60°C 70°C 80°C

PVC1016

7.512

69

6

ABS1016

7.512

7.512

710.5

69

7.5 6

HDPE1016

7.512

69.5

6

1) According to recognized standards for water supply on shore.

Table 4 Glass fibre reinforced epoxy 1) and polyester pipes (GRP). Permissible pressures andtemperature limits

Permissible working pressure(bar)

Minimum heat distortiontemperature of resin

ISO 75

Method A

Nominalpressure 2)

PN (bar) -50 to30°C 40°C 50°C 60°C 70°C 80°C 90°C 95°C

801015

25

1015

16

914

16

7.512

16

69.5

15

1001016

25

1016

16

1016

16

9.515

16

8.513.5

16

7.511

16

69.5

15

1351016

25

1016

16

1016

16

1016

16

1016

16

9.515

16

8.513.5

16

711

16

69.5

16

1) Minimum heat distortion temperature 135°C.2) According to recognized standards for marine use.

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2 Pumps

2.1 Relief valvesDisplacement pumps shall be fitted with relief valves. For pumps transporting flammable liquids, thedischarge from the relief valve is normally to be led back to suction side of the pump.

2.2 Hydrostatic testsPump housings shall be hydrostatically tested at a pressure of 1.5 times the maximum working pressure.However, the test pressure need not exceed the maximum working pressure by more than 70 bar.For centrifugal pumps the maximum pressure shall be the maximum pressure head on the head-capacitycurve. For displacement pumps the maximum working pressure is not to be taken less than the relief valveopening pressure.

2.3 Capacity tests

2.3.1 Pump capacities shall be checked with the pump running at design condition (rated speed and pressurehead, viscosity, etc.)Capacity test may be dispensed with for pumps produced in series when previous satisfactory tests havebeen carried out on similar pumps.For centrifugal pumps having capacities less than 1000 m3/h, the pump characteristic (head-capacity curve)shall be determined for each type of pump. For centrifugal pumps having capacities equal to or greater than1000 m3/h, the pump characteristic shall be determined over a suitable range on each side of the designpoint, for each pump.

2.3.2 Special survey arrangement for testing of pumps may be agreed upon.

3 Valves

3.1 Valve design

3.1.1 Drawings and specifications shall be submitted for approval for valves of new type or unconventionaldesign and for valves of welded construction fitted on ship’s side and bottom.

3.1.2 Pressure-temperature ratings for valves shall be in accordance with a recognized national standard.

3.1.3 Screwed-on valve bonnets are not to be used for valves on craft’s side and bottom and for valves insystems for flammable fluids.

3.1.4 Screwed-on valve bonnets shall be secured against loosening when the valve is operated.

3.1.5 Valves are normally to be closed by turning the handwheel clockwise.

3.1.6 Indicators shall be provided to show the open and closed position of the valve, unless this can beobserved in some other way, e.g. by a distinctly rising valve stem.

3.1.7 Handles on cocks shall be removable only when the cocks are in closed position.

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3.1.8 Welded necks of valve bodies shall be sufficiently long to ensure that the valves are not distorted asresult of welding and subsequent heat treatment of the joints.

3.2 Hydrostatic tests

3.2.1 All valve bodies shall be subjected by the manufacturer to a hydrostatic test at a pressure equal to1.5 times the nominal pressure (the nominal pressure is the maximum allowable working pressure at roomtemperature). The test pressure need not be more than 70 bar in excess of the nominal pressure.For valves fitted on craft’s side and bottom the test pressure is not to be less than 5 bar.

3.2.2 Butterfly valves fitted on craft’s side and bottom are also to be hydrostatically tested at a pressureequal to 5 bar applied independently on each side of the closed disc.

3.2.3 For valves fitted on craft’s side and bottom, the hydrostatic test shall be carried out in the presence ofthe surveyor or according to a special agreement (MSA).

3.2.4 For valves other than those mentioned in [3.2.3], the manufacturer’s certificate for hydrostatic testingwill be accepted.

4 Flexible Hoses

4.1 General

4.1.1 Flexible hose may only be used when necessary to admit relative movement between machinery andfixed piping system.

4.1.2 Fire tests are required for hoses intended for systems conveying flammable liquids or for use in seawater cooling systems.

4.1.3 Hoses of non-metallic materials used in systems containing flammable fluids or sea water shall have atleast one ply internal wire braid.

4.1.4 In fresh cooling water lines for diesel engines and compressors the requirements in [4.1.1] and [4.1.2]may be dispensed with provided each engine is arranged with an independent cooling system. Short rubberhoses with internal textile reinforcement fitted by means of hose clamps may be accepted.

4.1.5 Every hose shall be hydrostatically tested at a hydrostatic pressure of 1.5 times the working pressure.

4.2 Installation

4.2.1 Flexible hoses shall be accessible for inspection.

4.2.2 Flexible hoses shall be limited to a length necessary to provide for relative movement between fixedand flexibly mounted items of machinery/equipment or systems.

4.2.3 When used in systems conveying flammable fluids flexible hoses shall be shielded from hot surfacesand other sources of ignition.

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5 Detachable pipe connections

5.1 Flange connectionsFlanges with their pressure-temperature ratings in accordance with a recognized national standard willnormally be accepted.

5.2 Pipe couplings other than flanges

5.2.1 Mechanical joints including pipe unions, compression couplings, slip-on joints and similar joints shall becertified according to Sec.1 Table 2 for the service conditions and the intended application.

5.2.2 Threaded joints may be used for pipes with an outer diameter 60.3 mm and less with the exclusion ofpipes containing flammable fluids and pipes in systems with design pressure above 16 bar.

Guidance note:Threaded joint is defined as a joint where packed threads perform the sealing.


5.3 Expansion joints and bellows

5.3.1 Expansion joints and bellows are subject to approval for their intended use. The joints and bellowsshall be so designed and installed that pulling or blowing out is prevented.The pipeline in which an expansion joint or bellow shall be fitted, shall be adequately adjusted, aligned andclamped. When found necessary, protection against mechanical damage of the expansion joints may berequired.

5.3.2 The positions of expansion joints and bellows shall be clearly shown in the drawing of the pipingsystems.

5.3.3 Expansion joints and bellows are in general only to be used in readily accessible spaces. Exceptions tothe above are ballast tanks and pipe tunnels.

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SECTION 7 MANUFACTURE, WORKMANSHIP, INSPECTION ANDTESTING

1 Joining of plastic pipes

1.1 General

1.1.1 Joining of plastic pipes by welding, gluing, cementing, lamination or similar methods shall be carriedout by qualified personnel certified by the pipe manufacturer.

1.1.2 Satisfactory education and training shall be documented by a certificate issued by the pipemanufacturer.The certificate shall contain:

— the name of the holder— a statement confirming that the holder is considered qualified for a specified type of joining— reference to the pipe manufacturer’s joining procedure— date of issue and validity period— piping manufacturer’s stamp and signature of responsible person.

1.1.3 Prior to installation each operator shall, at the location, make at least one test joint representative ofthe joints to be used in the system. The ends of the joined pipe section shall be closed by flanges if such areincluded in the pipe system. The joined pipe section shall be exposed to an inside destructive hydrostaticpressure test of 5 times the design pressure of the pipe system, but not lower than 30 bars, for minimum5 minutes. There shall be no visual crazing, cracking or leakage. Special care shall be taken to inspect for«weeping» (sweating of water through the pipe wall). The procedure test shall be surveyed and approved bythe Society.

2 Welding and brazing

2.1 General

2.1.1 Welding of joints shall be carried out by qualified welders using approved welding procedures andwelding consumables.

2.1.2 Brazing of joints shall be carried out by qualified brazers using approved brazing procedures.

3 Hydrostatic tests of piping

3.1 Hydrostatic testing after assembly on boardThe piping shall be hydrostatically tested in the presence of the surveyor after installation on board,according to Table 1.

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Table 1 Hydrostatic testing after installation on board

Piping system Test pressure

Fuel oil piping

Heating coils in tanks

Bilge pipes

Steam pipes, compressedair pipes and feed pipes

1.5 x maximum workingpressure, minimum 4 bar

Hydraulic piping1.5 x maximum working pressureThe test pressure need not exceed the working pressure by morethan 70 bar

Piping systems made from non-metallic material(plastic)

1.5 x maximum working pressureMinimum 6 bar

Minimum duration 1 hour

4 Functional testing

4.1 GeneralAll piping systems shall be properly flushed, checked for leakage and functionally tested under workingconditions to the satisfaction of the surveyor.

5 Non-destructive testing

5.1 GeneralIn general, the welded joints including the inside wherever possible shall be visually examined. Non-destructive tests will be required for pipes with outer diameter greater than 76.1 mm as indicated below:Butt welded jointsFor pipes containing flammable fluids or steam with design pressure above 7 bar, or other media with designpressure above 16 bar, at least 10% random radiographic testing.Fillet weldsFor pipes containing flammable fluids or steam with design pressure above 7 bar, or other media with designpressure above 16 bar, at least 10% random magnetic particle testing.

DNV GLDriven by our purpose of safeguarding life, property and the environment, DNV GL enablesorganizations to advance the safety and sustainability of their business. We provide classification andtechnical assurance along with software and independent expert advisory services to the maritime,oil and gas, and energy industries. We also provide certification services to customers across a widerange of industries. Operating in more than 100 countries, our 16 000 professionals are dedicated tohelping our customers make the world safer, smarter and greener.

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