Section 2 Construction and installation

2.1.1 All pipes for essential services are to be secured in position to prevent chafing or lateral movement.

2.1.2 Long or heavy lengths of pipe are to be supported by bearers so that no undue load is carried by pipe connections or pumps and fittings to which they are attached.

2.2.1 Suitable provision for expansion is to be made, where necessary, in each range of pipes.

2.2.2 Where expansion pieces are fitted, arrangements are to be provided to protect against over extension and compression. The adjoining pipes are to be suitably aligned, supported, guided and anchored. Where necessary, expansion pieces of the bellows type are to be protected against mechanical damage.

2.2.3 Expansion pieces of an approved type incorporating oil resistant rubber or other suitable synthetic material may be used in cooling water lines in machinery spaces. Where fitted in sea-water lines, they are to be provided with guards which will effectively enclose, but not interfere with, the action of the expansion pieces and will reduce to the minimum practicable any flow of water into the machinery spaces in the event of failure of the flexible elements. Where the provision of such guards is not practicable, consideration will be given to alternative arrangements which provide an equivalent level of protection. Proposals to use such fittings in water lines for other services, including:

• ballast lines in machinery spaces, in duct keels and inside double bottom water ballast tanks, and
• bilge lines inside duct keels only,

will be specially considered when plans of the pumping systems are submitted for approval.

2.2.4 For requirements relating to flexible hoses, see Pt 15, Ch 1 Piping Design Requirements.

2.3.1 Valve chests, cocks, pipes or other fittings attached direct to the plating of tanks, and to bulkheads, flats or tunnels which are required to be of watertight construction, are to be secured by means of studs or tap bolts screwed through bulkhead pieces welded to the plating, and not by bolts passing through clearance holes. For tanks, the stud or tap bolt holes are not to penetrate the plating.

2.3.2 For composite hulls, see Pt 15, Ch 2, 14.4 Fittings for composite hulls 14.4.5.

2.4.1 All pipes situated in cargo spaces, chain lockers or other positions where they are liable to mechanical damage are to be efficiently protected.

2.4.2 So far as practicable, pipelines, including exhaust pipes from engines, are not to be routed in the vicinity of switchboards or other electrical appliances in positions where the drip or escape of fluids, gas or steam from joints or fittings could cause damage to the electrical installation. Where it is not practicable to comply with these requirements, drip trays or shields are to be provided as found necessary.

2.5.1 After installation on board, all steam, hydraulic, compressed air and other piping systems covered by Pt 15, Ch 1, 2.1 Plans and information together with associated fittings which are under internal pressure, are to be subjected to a running test at the intended maximum working pressure.