KNF N963, Operating And Installation Instructions

Page: 26 / 32

Troubleshooting Diaphragm Pump N936
26 Translation of Original operating and installation instruction, English, KNF 320276-320275 09/19
Flow rate, pressure or vacuum too low
The pump does not achieve the flow rate specified in the technical specifications or
in the data sheet.
Cause Fault remedy
Condensate has collected in the
pump head.
à
Separate the source of the condensate from the
pump.
à
Flush the pump with air at atmospheric pressure
for a few minutes (if necessary for safety reasons:
with an inert gas).
à
Install pump at the highest location in the system.
There is overpressure on the pres-
sure side and at the same time
vacuum or pressure above atmo-
spheric pressure on the suction
side.
à
Change the pneumatic conditions.
Pneumatic lines or connection
parts have insufficient cross sec-
tion or are throttled.
à
Disconnect pump from the system to determine
the output values.
à
Eliminate throttling (e.g., valve) if necessary.
à
Use lines or connection parts with larger cross
section if necessary.
Leaks occur at connections, lines
or pump head.
à
Eliminate leaks.
Connections or lines are com-
pletely or partially plugged.
à
Check connections and lines.
à
Remove the parts and particles that are causing
the plugging.
Head parts are soiled.
à
Clean head components.
Working diaphragm broken
à
Stop pump immediately.
Diaphragm or reed valves are worn
or defective.
à
Replace diaphragm and reed valves (see Chapter
Changing diaphragm and reed valves).
Diaphragm, valves or O-rings are
worn or defective.
à
Changing diaphragm, valves or O-ring (see
Chapter
9.3 Replacing diaphragm, valves and O-
rings ).
Tab. 14
Fault cannot be rectified
If you are unable to identify any of the specified causes, send the pump to
KNF Customer Service (contact data: see www.knf.com).
1. Flush pump with air at atmospheric pressure for a few minutes (if nec-
essary for safety reasons: with inert gas) to free the pump head of dan-
gerous or aggressive gases (see Chapter
9.2.1 Flushing the pump ).
2. Remove pump.
3. Clean the pump (see Chapter 9.2.2 Cleaning the pump ).
4. Send the pump together with completed Health and Safety Clearance
and Decontamination Form to KNF, stating the nature of the trans-
ferred medium.