4
Suction Limitations
Theoretically, no pump can lift water higher than 9 metres (30 ft) verti-
cally, and the practical limit is approximately 6 metres (20 ft), depend-
ing on the installation.
The pump is equipped with an internal suction flap valve. If pump fails
to prime, it could be due to a leak in the suction pipe, a worn impeller
or too great a suction lift. Self priming pumps do not self prime when
subject to a high discharge head. Under these conditions the suction
flap valve should be removed and a foot valve installed on the end of
the suction line.
Suction Strainer
For portable pump use, a suction hose strainer must be used. This
removes the risk of gravel or large pieces of foreign matter entering and
damaging the pump.
Type of Water
Pumps are capable of pumping septic tank effluent, sink wastes, small
amounts of dirt or sand, drainage or polluted water and some industrial
wastes. They are not designed to pump large quantities of foreign mat-
ter. If fluid contains large or stringy material, then an adequate suction
strainer should be used.
If chemicals are to be pumped, compatability of pump material should
be checked with your local onga office.
SERVICE
Pump runs but fails to pump water:
1) Check for an air leak in suction pipe.
2) The pump has not been filled with water.
3) Water has evaporated leaving pump dry.
4) Foreign matter has clogged the impeller or pipe.
5) Suction lift too high.
