PIPING IN SHIPS

Copper-Nickel-Iron Alloy Piping (90/10) is used for the piping of the saltwater main and its branches, sanitary system, hangar and magazine spraying systems, hull and fire, fire and bilge, and hangar spray pump sea suctions, risers, overboard discharges and pump leak-offs, overboard discharges from water/fuel displacement systems, salt water supply to and overboard discharges from bathroom ejectors, bathroom drains within the bathroom (except as stated below) and urinal drains.

Galvanized Mild Steel Piping is used for all suctions to compartments, overboard discharges of salvage pump systems, suction stand pipes, ejector suctions to bathroom sumps, portable diesel pump sea suction, scuppers and drains, soil pipes, suction pipes within fresh water storage tanks, oil fuel residue suctions, air escape pipes, and all pipes within FFO tanks where the tank structure is galvanized. Steel pipes below 11/2-inch bore are connected by screwed sleeves and large pipes by flanges welded to the pipes, the flanges being welded prior to galvanizing.

Copper-Nickel-Iron Alloy Piping is connected as follows by flanges if the bore is 2 inches or more and smaller pipes by brazed core unions, capillary type fittings or compression fittings of the non-manipulative type. Ferrous fittings are not fitted in copper-nickel-iron systems. Copper and coppernickel- iron pipes are kept clear of aluminium alloy structure. At least 1/2 inch is provided between the pipes or the pipe insulation and the structure. Corrosion pieces, consisting of renewable 12-inch lengths of galvanized mild steel, are fitted between dissimilar metals in such piping normally dealing with salt water such as suctions to gland and plummer block compartments but are not normally required in dry suction systems.

No non-ferrous piping is introduced into any part of the ship so low as to come into contact with bilge water. Unless unavoidable, pipes containing liquid are kept out of compartments accommodating important electrical apparatus. The seating of pipe joints directly above electrical equipment is prohibited. No electrical installation is earthed to any water system and electric cables or associated fittings are not attached to such piping. Pipes connected to the outer bottom or to protective bulkheads are worked with generous bends, or alternatively with weakened shearing joints, so that they cannot act as struts in the vent of deflection of the structure.