Section 2 Construction and installation

2.1.1 Except where otherwise stated in this Chapter, pipes, valves and fittings are to be made of steel, cast iron, copper, copper alloy, or other approved material suitable for the intended service.

2.1.2 Where applicable, the materials are to comply with the relevant requirements of Pt 5, Ch 10 Piping Design Requirements.

2.1.3 Materials sensitive to heat, such as aluminium, lead or plastics, are not to be used in systems essential to the safe operation of the ship, or for containing combustible liquids or water where leakage or failure could result in fire or in the flooding of watertight compartments, see Pt 5, Ch 10 Piping Design Requirements for plastic pipes.

2.1.4 Aluminium alloy pipes are not acceptable for fire extinguishing pipes unless they are suitably protected against the effect of heat. The proposed use of aluminium alloy with appropriate insulation will be considered when it has been demonstrated that the arrangements provide equivalent structural and integrity properties compared to steel. In open and exposed locations where the insulation material is likely to suffer from mechanical damage suitable protection is to be provided.

2.2.1 The minimum nominal wall thickness of steel, copper, copper alloy and stainless steel pipes is to be in accordance with Pt 5, Ch 10 Piping Design Requirements.

2.2.2 Special consideration will be given to the wall thicknesses of pipes made of materials other than mentioned in Pt 5, Ch 11, 2.2 Pipe wall thicknesses 2.2.1.

2.3.1 Valves and cocks are to be fitted in places where they are at all times readily accessible, unless otherwise specifically mentioned in the Rules. Valves in cargo oil and ballast systems may be fitted inside tanks, subject to Pt 5, Ch 11, 2.3 Valves - Installation and control 2.3.2.

2.3.2 All valves which are provided with remote control are to be arranged for local manual operation, independent of the remote operating mechanism. For shipside valves and valves on the collision bulkhead, the means for local manual operation are to be permanently attached. For submerged valves in cargo oil and ballast systems, as permitted by Pt 5, Ch 11, 2.3 Valves - Installation and control 2.3.1, local manual operation may be by extended spindle or a portable hand pump. Where manual operation is by hand pump, the control lines to each submerged valve are to incorporate quick coupling connections, as close to the valve actuator as practicable, to allow easy connection of the hand pump. Not less than two hand pumps are to be provided.

2.3.3 In the case of valves which are required by the Rules to be provided with remote control, opening and/or closing of the valves by local manual means is not to render the remote control system inoperable.

2.3.4 For general requirements of valves, see Pt 5, Ch 10, 6 Valves.

2.3.5 Remote controls of valves on passenger ships situated above the bulkhead deck are to be clearly indicated.

2.4.1 Valve chests, cocks, pipes or other fittings attached directly to the plating of tanks and to bulkheads, which are required to be of watertight construction, are to be secured by means of studs screwed through the plating or by tap bolts, and not by bolts passing through clearance holes. Alternatively, the studs or the bulkhead pieces may be welded to the plating.

2.4.2 For requirements relating to valves on the collision bulkhead, see Pt 5, Ch 11, 3.5 Fore and after peaks 3.5.3.

2.5.1 All water inlet and overboard discharge pipes are to be fitted with valves or cocks secured directly to the shell plating, or to the plating of fabricated steel water boxes attached to the shell plating. These fittings are to be secured by bolts tapped into the plating and fitted with countersunk heads, or by studs screwed into heavy steel pads fitted to the plating. The stud holes are not to penetrate the plating.

2.5.2 Valves for ship-side applications are to be installed such that the section of piping immediately inboard of the valve can be removed without affecting the watertight integrity of the hull.

2.5.3 Distance pieces of short, rigid construction, and made of approved material, may be fitted between the valves and shell plating. The thickness of such pipes is to be not less than:

1. Shell thickness for pipes smaller or equal to NB 50.

2. Shell thickness plus 2 mm for pipes greater than NB 50.

In addition to the above, the following conditions are to be met:

• Distance pieces are to be efficiently protected against corrosion.
• Distance pieces of steel may be welded to the shell plating.
• Details of the welded connections and of fabricated steel water boxes are to be submitted.

2.5.4 Gratings are to be fitted at all openings in the ship’s side for inlet valves and inlet water boxes. The net area through the gratings is to be not less than twice that of the valves connected to the inlets.

2.5.5 Water inlet and overboard discharge valves and cocks are in all cases to be fitted in easily accessible positions, and so far as practicable, are to be readily visible. Indicators are to be provided local to the valves and cocks, showing whether they are open or shut. The valve spindles are to extend above the lower platform.

2.5.6 Ship-side valves and fittings, if made of steel or other approved material with low corrosion resistance, are to be suitably protected against wastage.

2.5.7 Valves, cocks and distance pieces, intended for installation on the ship’s side below the load waterline, are to be tested by hydraulic pressure to not less than 5 bar.

2.6.1 Bilge, ballast and cooling water suction and discharge pipes are to be permanent pipes made in readily removable lengths with flanged joints, except as mentioned in Pt 5, Ch 11, 7.8 Bilge pipes in way of deep tanks, and are to be efficiently secured in position to prevent chafing or lateral movement. For joints in fuel oil piping systems, see Pt 5, Ch 12, 4.4 Pipes conveying oil.

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

2.7.2 Where expansion pieces are fitted, they are to be of an approved type and are to be protected 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.

2.7.3 Expansion pieces of an approved type incorporating special quality oil resistant rubber or other suitable synthetic material may be used in cooling water lines in machinery spaces. Where fitted in water inlet 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. Proposals to use such fittings in water lines for other services will be specially considered when plans of the pumping systems are submitted for approval.

2.7.4 For requirements relating to flexible hoses, see Pt 5, Ch 10, 7 Flexible hoses.

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

2.8.2 So far as is practicable, pipelines, including exhaust pipes from engines, are not to be led in the vicinity of switchboards or other electrical appliances. Where it is not practicable to comply with these requirements, drip trays or shields are to be provided as found necessary. Short sounding pipes to tanks are not to terminate near electrical appliances, see Pt 5, Ch 11, 10.12 Short sounding pipes 10.12.3.

2.9.1 After installation on board, all steam, hydraulic, compressed air and other piping systems covered by Pt 5, Ch 11, 1.2 Prevention of progressive flooding in damage condition 1.2.1, together with associated fittings which are under internal pressure, are to be subjected to a running test at the intended maximum working pressure.

2.10.1 For guidance on metal pipes for water services, see Pt 5, Ch 10, 11 Guidance notes on metal pipes for water services.