Diesel engine fresh water cooling system

Diesel engine fresh water cooling system:

slow and medium speed engine use fresh water to circulate and cool the cylinder jacket covers,
pistons, exhaust valves(if fitted) and turbocharger as these parts subjected to work under high
temperature and pressure conditions, cooling is required to prevent the overheating of these parts
fresh water is most common medium employed. fresh water may cause the deposits of salt on
heated surfaces resulting pitted and corrosion and pitting circulating water is cooled in the
cooler by passing sea water in the coolers.

jacket cooling water system:

This system forms closed circuit water passing from the engine returns through cooler to pump
suction and then back to engine. A header and expansion tank is placed at a reasonable height
to allow venting and pressurizing of the system. This is connected to both the engine discharge
and the pump suction line. A heater is included with a bypass and the system can warm the engine
when necessary.

cooling water enters at the lower end of the cylinder jackets passing upto connection from the
top of the jacket to the cyclinder covers and the exhaust valves( if fitted). A restricted
amount of water is taken from this discharge and passes through turbocharger cooling spaces