
Troubleshooting
Type of fault
38
Stepper motor-driven diaphragm dosing pump NXP-M and NXP-P
Operating instructions
13.1.7 Diaphragm is torn or tears too often
Possible cause
Remedy
Shut-off valves closed.
è
Open the shut-off valves. Inspect
the dosing pump for possible
damage.
Pressure peaks due to
acceleration with long suction
lines.
è
Install a suction pressure
regulator.
The materials are not suitable
for the dosing medium being
used.
è
Check the resistance of the
materials.
Diaphragm not screwed up to
the end stop on the dia-
phragm rod.
è
Screw a new diaphragm up to the
end stop.
System backpressure too
high (measured at discharge
connection of dosing pump).
è
Clean blocked injection nozzle.
è
Install pulsation dampeners to
reduce pressure peaks if pipes
are too long.
è
Check function of safety valves.
Media sediment in dosing
head.
è
Clean the dosing head.
Table 35: Type of fault: Diaphragm is torn or tears too often