Hong Kong Regulations

MERCHANT SHIPPING (INSTRUCTIONS TO SURVEYORS) (PASSENGER SHIPS) REGULATIONS - REGULATION 48

Main and auxiliary inlets and discharges

(1) These shall be so arranged as to prevent accidental admission of water
into the ship.

(2) Cocks or valves are to be fitted between the pipes and the shell plating.
They must be attached to the latter and so arranged that they can be easily
and expeditiously opened or closed at any time. The cocks, valves and the
whole lengths of the pipes connected to them shall be accessible at all times.

(3) To prevent the accidental admission of water into the ship owing to the
fracture of main or auxiliary inlet or discharge valve chests which if
fastened directly to the skin of the ship would require to have long necks,
such chests are to be made with the necks as short as practicable and are to
be attached to wrought steel boxes built on to the skin of the ship. Chests
having other than short necks are to be made of cast steel.

(4) Shipside cocks and valves related to main and auxiliary machinery or
boilers shall not be of ordinary cast iron. Consideration will be given to the
case of special grades of cast iron provided that full particulars are
submitted for the approval of the Principal Surveyor  of Ships. Steel valves
must be suitably protected against corrosion. (G.N.A. 169 of 1950)