Swing Piston Pumps NPK 09
Trouble Shooting
11
7. Trouble
Shooting
Before working on the pump isolate the power supply se-
curely, then check that the lines are not live.
The following tips for fault-finding are best employed in the se-
quence shown.
Pump produces no flow
Thermal switch has operated following over-heating.
`
Disconnect pump from mains and allow to cool.
Trace cause of over-heating and eliminate it.
Connections or lines are blocked
An external valve is closed, or a filter blocked.
Liquid (condensate) has collected in the pump head.
Piston seal or valve plate is/are worn.
`
Section
5. Servicing
.
Flow, pressure, or vacuum too low
Compare the actual performance with the figures in section
10 or the data sheet.
There is pressure on the pressure side, and at the same
time vacuum, or a pressure above atmospheric, on the
suction side.
`
The pump is not designed for this condition.
The internal diameter of connecting tubing or connected
components, or connected components is too small, or
they are restricted.
`
In order to measure performance, the pump must
be disconnected from the system (small diameter
tubing or a valve can significantly affect perform-
ance).
There is a leak at a connector, in a line, or in the pump
head.
Piston seal or valve plate is/are worn, or dirt is in the head
(see section
5. Servicing
).
If the pump does not operate properly and you cannot find any of
the above faults, send it to the KNF Service Department.
