The Pipe Work For Self Priming And Air-Handling Pumps - Packo AX Instruction Manual

connection in the bracket. This must be con-
nected directly to the suction vessel with no rise
in the pipework and no valves should be fitted.
At the top of the column there are two nipples,

4.6. The pipe work for self priming and air-handling pumps

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A good operation for self-priming pumps (types
MSP) and air handling pumps (types CRP, PRP
and IRP) depends on the design of the discharge
pipe. It is necessary that the air on the outlet of
the pump can evacuate freely via the discharge
pipe to the discharge vessel or the environment.
When bridges (a part of a pipe that has both ends
lower than the middle) occur in the discharge
pipe, the air that the pump processes collects
in these bridges and the pump will loose its
self-priming and respective air handling capacity.
The self-priming and air handling capacities are
restricted by the static pressure on the discharge
side of the pump. A MSP can create maximum
3 to 5 meter vacuum on the inlet of the pump,
depending on the type. The speed, by which this
vacuum is achieved, depends on the diameter
and length of the suction line. The larger the
volume of air that has to be handled, the longer
it will take. Of this maximum achievable vacuum
max. 5 m
at least one of these must be left open as an
emergency overflow to prevent liquid coming
into contact with the motor.
the pressure that occurs during suction on the
outlet of the pump (water column), has to be
diminished. Consequently, a water column that
stands on a one-way valve in the discharge pipe
is very disadvantageous. Put the one-way valve
on the inlet of the pump. A CRP, PRP or IRP
pump can only handle air as long as the pressure
on the outlet of the pump is smaller than 5 meter
liquid column. Put the one-way valve also here
on the inlet of the pump.
Since an air-handling pump has no water retain-
ing vessel, special attention has to be paid to the
pipe work in case the pump is not installed with a
flooded suction. The pipe work has to make sure
there remains enough water in the pump casing
when the pump is switched off to give the pump
its air-handling capacity on the next start-up.
For pumps lifting the liquid over a rim, a swan-
neck is created. Important is that the inlet of the
pump comes lower than the end of the pipe in
the suction vessel.
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