Section 7 Engine cooling water systems

7.1.1 Provision is to be made for an adequate supply of cooling water to the main propelling machinery and essential auxiliary engines, also the lubricating oil and fresh water coolers, where these coolers are fitted. The cooling water pump(s) may be worked from the engines or be driven independently.

7.2.1 Where cooling water pumps can develop a pressure head greater than the design pressure of the system, they are to be provided with relief valves on the pump discharge to effectively limit the pump discharge pressure to the design pressure of the system.

7.3.1 Not less than two water inlets are to be provided for the pumps supplying the cooling water system.

7.3.2 Cooling water pump inlets are to be low inlets.

7.4.1 Where outboard water is used for the direct cooling of the main engines and essential auxiliary engines, the cooling water suction pipes are to be provided with strainers which can be cleaned without interruption to the cooling water supply.

7.5.1 Box coolers with the top of the inlet chest less than 400 mm above the waterline shall not be dismounted when the ship is afloat. A legible name plate is to be fitted in a prominent position to that effect.

7.5.2 Box coolers with the top of the inlet chest exceeding 400 mm may be dismounted when the ship is afloat with permission of the skipper. A legible name plate is to be fitted in a prominent position to that effect.

7.5.3 Box cooler chests are to be provided with a suitable de-aeration pipe of extra heavy gauge with an approved shipside valve. The pipe is to be led to above the waterline.

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