Raw Water Pump; Air Intake Silencer - Westerbeke 22.0 EDE 60Hz Operator's Manual

COOLING SYSTEM
RAW WATER COOUNG CIRCUIT
The raw water flow is created by a positive displacement
impeller pump. This pump draws water directly from the
ocean, lake, or river from a thru-hull opening through a hose
to the water strainer. The raw water passes from the strainer
through the pump to the heat exchanger (through the heat
exchanger tubes) where it ::ools the engine's circulating fresh
water coolant. The raw water is then discharged into the
water-injected exhaust elbow, mixing with and cooling the
exhaust gasses. This mixture of exhaust gas and raw water is
driven through the exhaust system and overboard.
Raw Water Pump
The raw water pump is a self-p(iming, rotary pump with a
non-ferrous housing and a Neoprene impeller. The impeller
has flexible blades which wipe against a curved cam plate
within the impeller housing, producing the pumping action.
On no account should this pump be run dry. There should
always be a spare impeller and impeller cover gasket aboard
(an impeller kit). Raw water pump impeller failures occur
when lubricant (raw water) is not present during engine
operation. Such failures are not warrantable, and operators
are cautioned to make sure raw water flow is present at
start-up. The raw water pump should be inspected
periodically for broken or tom impeller blades. See
MAINTENANCE SCHEDULE.
CHANGING THE RAW WATER PUMP IMPELLER
1. Close the raw water intake valve and unfasten the two
hose connection on the inlet and outlet nipples of the
pump.
2. Remove the cap screws and hold down brackets that
secure the pump to the front gear case and lift the pump
off the engine. Check the pump's shaft drive tang for wear
and also the drive in the engine.
3. Remove the three cap screws that secure the impeller
housing to the pump body (note the position of the
housing to the pump body) and remove the housing ·
exposing the sea water impeller.
4. Pull the impeller off the keyed shaft and install the
replacement.
5. Lightly coat theinside of the impeller housing with
glycerine lubricant. Check the condition of the housing
sealing 0-ring. Replace if needed.
6. Replace the impeller housing over the impeller
positioning it correctly on the body and secure it in place
with the three cap screws.
7. Secure the pump onto the gear case aligning the pump's
shaft tang with the drive slot.
8. Reattach the water hoses and open the water intake
valve. Run the unit and check for leaks.
IMPELLER
INSPECTION: CHECK AT THE BASE
EACH BLADE BY BENDING VIGOROUSLY.
REPLACE THE IMPELLER IF THERE
ARE ANY CRACKS.
WHEN INSTALLING: TAKE CARE TO ALIGN .
THE IMPELLER KEYWAY WITH THE SHAFT
KEY. FOLD THE IMPELLER BLADES IN
EITHER DIRECTION (THEY WILL TURN IN ·
THE CORRECT POSITION WHEN THE
IMPELLER STARTS TO ROTATE).
RAW WATER PUMP
#042175
IMPELLER-COAT
BLADES WITH
GLYCERINE
HOUSING
IMPELLER KIT
#200175
AIR INTAKE/SILENCER
The air intake port supplies cooling air to the control panel
electronics. this air flow continues to the engines air
intake/silencer to supply fresh air to the engine.
This system requires NO maintenance.
AIR INTAKE PORT
KEEP FREE FROM
OBSTRUCTION
NOTE: If the unit is being operated
in
an area where air born contaminants
(silicon) are present. An external air filter
must be added.
CONTROL PANEL
AIR INTAKE
SILENCER
Engines & Generators
18