Cooling - sea water inlet system

Your engine is fitted with a gear driven sea water pump which sucks in seawater (raw water) to cool the closed circuit system via the heat exchanger.

1. It is very important that the seawater inlet should have a strainer system either built into the sea cock or a high level system with visual inspection glass (as shown) mounted just above the water line. 2. The inlet sea cock should be 1” BSP to which a 7/8” / 22 mm hose connector can be fitted. The sea water pump is 22 mm OD to suit the 22 mm ID hose. 3. Good access to the inlet sea cock is essential so that plastic bags or seaweed trapped in the intake can be poked out. 4. All pipe work should have approved marine grade stainless steel hose clips. Any loose clamps or bad connections can cause flooding and sinking of the vessel 5. If water is required for stern tube lubrication then this should be taken from a ‘T’ piece in the pipe going from the heat exchanger outlet to the water injection bend. 6. Scoop type water pickups should never be used, as water will be forced through the pump and into the exhaust system whilst the vessel is sailing. This is very dangerous as the exhaust will eventually fill and sea/raw water will back up into the engine through the exhaust valve.

Catastrophic failure will result as soon as the engine is restarted. Note: The maximum lift of the sea water pump is 2m when primed.

10

Water Level

Canal Boats with Keel Coolers

Keel cooling is available as an option with all our engines. Most narrowboats on English canals have keel cooling. Some estuaries and ports have fine silt and mud that block normal heat exchanger cooling systems, requiring a keel cooling solution also for some work boats, etc. The Beta 10 to Beta 25 propulsion engines arranged for keel cooling have both engine supply and return copper pipes of 22mm diameter; requiring flexible rubber hoses with a 22mm bore. These rubber hoses should be designed and manufactured as hot water heater hoses suitable for operation up to 100 degrees centigrade Narrowboats: With keel cooling the coolant (same fresh water / antifreeze solution as heat exchanger cooling) flows around the engine and also the keel cooling tanks, before returning to the engine. These keel cooling tanks are normally welded into the ‘swim’ of the narrowboat, using the 8mm steel plate hull as one side of the tank to transfer the engine heat to the canal. The required surface area for keel cooling our engines in narrowboats is as detailed.