Cooling - Sea Water Inlet System; Cooling - Keel Cooling System 10 - Beta Marine Beta 10 Operator's Maintenance Manual

Seawater Inlet System (Heat exchanger Cooled Engines)
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
/ 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
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Water Level
Canal Boats with Keel Cooling
The Beta 10 to Beta 25 propulsion engines are available
with keel cooling if required. The keel cooling supply
and return pipes are 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.
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
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/ " will be forced through the pump and into the exhaust
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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.
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 water. The required
surface area for keel cooling our engines in narrowboats
is as detailed.
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