Diaphragm Vacuum Pumps N86.16
Troubleshooting
Translation of original Operating and Installation Instructions, english, KNF121260-121531 04/20
25
Flow rate, pressure or vacuum too low
The pump does not achieve the output specified in the Technical data or the data sheet.
Cause
Fault remedy
Condensate has collected in the
pump head.
Separate the source of the condensate from the pump.
Flush the pump with air at atmospheric pressure for a few
minutes (if necessary for safety reasons: with an inert gas).
Install the pump at the highest point in the system.
There is overpressure on the
pressure side and at the same
time vacuum or pressure above
atmospheric pressure on the
suction side.
Change the pneumatic conditions.
Pneumatic lines or connection
parts have insufficient cross
section or are throttled.
Disconnect pump from the system to determine the output
values.
Eliminate throttling (e.g. valve) if necessary.
Use lines or connection parts with larger cross section if
necessary.
Leaks occur at connections,
lines or pump head.
Eliminate leaks.
Connections or lines are com-
pletely or partially plugged.
Check connections or lines.
Remove the parts and particles that are causing the plug-
ging.
Head parts are soiled.
Clean head components.
Diaphragm broken.
Stop pump immediately.
Diaphragm or valve plates are
worn or defective.
Replace working diaphragm, safety diaphragm and reed
valves (see Chapter 9.3).
Tab. 13
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 necessary for safety reasons: with inert gas) to free the
pump head of dangerous or aggressive gases (see Chapter
9.2.1).
2. Clean the pump (see Chapter 9.2.2).
3. Send the pump together with completed Health and Safety
Clearance and Decontamination Form to KNF, stating the na-
ture of the transferred medium.
