Boilers and other pressure vessels
(1) In every ship every boiler or other pressure vessel and its respective mountings shall, before being put into service for the first time, be subjected to a hydraulic test to a pressure suitably in excess of the working pressure which will ensure that the boiler or other pressure vessel and its mountings are adequate in strength and design for the service for which it is intended and having regard to -
(a) the design and the material of which it is constructed;
(b) the purpose for which it is intended to be used; and
(c) the working conditions under which it is intended to be used;
and every such boiler or other pressure vessel and its respective mountings shall be maintained in an efficient condition.
(2) In every such ship provision shall be made which will facilitate the cleaning and inspection of every pressure vessel.
(3) (a) Means shall be provided which will prevent overpressure in any part of boilers and other pressure vessels, and in particular every boiler and every unfired steam generator shall be provided with not less than two safety valves.
(b) The Administration may, having regard to the output or any other feature of any boiler or unfired steam generator, permit only one safety valve to be fitted if it is satisfied that adequate protection against overpressure is provided.
Additional requirements for ships constructed on or after 1 September 1984
(4) Every unattended oil fired boiler shall be provided with arrangements to shut off the fuel supply and give an alarm at an attended location in the event of low boiler water level, combustion, air supply failure or flame failure.
(5) Every boiler designed to contain water at a specific level shall be provided with at least two means for indicating the water level, at least one of which shall be a direct reading gauge glass.
(6) Every water-tube boiler serving turbine machinery shall be fitted with a high water level alarm.
(7) Means shall be provided to test and control the quality of the water in boilers.
Boiler feed systems
(1) Every boiler which provides services essential for the safety of the ship and which would be rendered dangerous by the failure of its feed water supply shall be provided with not less than two efficient and separate feed water systems so arranged that either of such systems may be opened for
inspection or overhaul without affecting the efficiency of the other and means shall be provided which will prevent overpressure in any part of the systems.
(2) (a) Every feed check valve, fitting, or pipe through which feed water passes from a pump to such boilers shall be designed and constructed to withstand the maximum working stresses to which it may be subjected, with a factor of safety which is adequate having regard to the material of which it is constructed and the working conditions under which it will be used.
(b) Every such valve, fitting, or pipe shall, before being put into service for the first time, be subjected to a hydraulic test suitably in excess of the maximum working pressure of the boiler to which it is connected or of the maximum working pressure to which the feed line may be subjected, whichever shall be the greater, and shall be maintained in an efficient condition.
(c) The feed pipes shall be adequately supported.
(3) Where in any ship it is possible for oil to enter the feed water system of a boiler, the arrangements for supplying boiler feed water shall provide for the interception of oil in the feed water.
Additional requirements for ships constructed on or after 1 September 1984
(4) Means shall be provided to test and control the quality of the feed water to boilers.
Steam pipe systems
(1) In every ship every steam pipe and every fitting connected thereto through which steam may pass shall be so designed and constructed as to withstand the maximum working stresses to which it may be subjected, with a factor of safety which is adequate having regard to –
(a) the material of which it is constructed; and
(b) the working conditions under which it will be used.
(2) Without prejudice to the generality of the foregoing, every steam pipe or fitting shall, before being put into service for the first time, be subjected to a test by hydraulic pressure to a pressure suitably in excess of the working pressure to be determined having regard to the requirements of subsubRules (1)(a) and (b) and every such steam pipe or fitting shall be maintained in an efficient condition.
(3) Steam pipes shall be adequately supported.
(4) Provision shall be made which will avoid excessive stress likely to lead to the failure of any such steam pipe or fitting, whether by reason of variation in temperature, vibration or otherwise.
(5) Efficient means shall be provided for draining every such steam pipe so as to ensure that the interior of the pipe is kept free of water and that water hammer action will not occur under any condition likely to arise in the course of the intended service of the ship.
(6) Where a steam pipe is connected to any source at a higher pressure than it can otherwise withstand with an adequate factor of safety, an efficient reducing valve, relief valve and pressure gauge shall be fitted to such pipe.
