Clarke PW2, Operating & Maintenance Instructions, Page: 6 / 24

6
GENERAL USE OF THE PUMP
1. Connect the suction and discharge hoses to the pump housing using the hose clamps and
gaskets supplied to achieve an airtight seal. There must be no damage of any kind to the
hoses which must be well protected and supported.
NOTE: Hoses or pipes should be supported independently and not carried by the pump.
IMPORTANT: An air leak in the suction line will prevent priming, and reduce the capacity of the
pump.
2. Pay particular attention to the following:
a. Always ensure the hose adaptor gasket is in place, and correctly fitted.
b. Always use a flexible hose at the pump body connection, of at least 1ft (300mm).
c. Keep all pipes/hoses as short and straight as possible, and avoid sharp bends.
d. If a flexible hose must be laid across a roadway, protect it with planking.
e. Ensure there is adequate drainage for the discharged water.
(Instantaneous shut off pressure, applied when a vehicle runs across an unprotected
hose, will cause “hydraulic shock”, which can damage the pump and/or the hose).
3. Attach the suction strainer to the end of suction hose using a further hose clamp, to prevent
large stones etc, from being drawn up which could cause severe damage. Keep the strainer
clean. If it is likely to clog with dirt or debris, proceed by either:
a. Preparing a bed of stones on which to rest the strainer.
b. Tying the strainer so that it stays off the bottom of the pit, pond or excavation.
c. Tie the strainer inside a basket or bucket.
4. Remove the filler plug on top of the pump case and prime the pump with water, leaving no
air gap. Remember the pump is self-priming only when the pump is filled. It will prime and
re-prime itself without refilling. Refilling is necessary only if the pump has been drained or if
the water has been lost. Never allow the pump to run dry.
5. If the discharge line runs vertically more than 30ft it is advisable to install a check valve in
the discharge line near the pump to stop destructive water hammer when the pump is shut
down. If a check valve is installed, it may also be necessary to vent the top of the pump so
that air can he expelled during automatic re-priming. This air bleed may he accomplished by
providing a 1/4" line from the top of the pump back to the liquid source. We will not assume
any responsibility for damage to the pump if no check valve is used in the discharge line.
Properly fuelled and lubricated your pump will run without attention.