KNF N 143 AN.12 E, Operating And Installation Instruction

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Diaphragm Pumps N 143/186.12 Operation
Translation of original Operating and Installation Instructions, english, KNF 121610-121613 07/16 19
DANGER
Dangerous gas mixtures may form if the working
diaphragm ruptures
If the working diaphragm ruptures, the medium will
mix with the air located in the innerspace between
the working diaphragm and the safety diaphragm.

If the working diaphragm ruptures, stop the
pump immediately. By monitoring the innerspace
between the working diaphragm and the safety
diaphragm, rupture of the working diaphragm
can be detected on the basis of a change in
pressure in the innerspace. Even if the pressure
or flow rate of the pump changes without any
apparent cause, this too can mean that the work-
ing diaphragm is ruptured.

The working diaphragm and the safety dia-
phragm must be replaced before continuing with
operation (see chapter 8, Maintenance).
WARNING
Automatic starting can cause personal injury and
pump damage
When the operation of the pump is interrupted by the
thermal switch, the pump will restart automatically
after cooling down.

Take all necessary care to prevent this leading
to a dangerous situation.

With the pump at a standstill, open pressure and suction lines
to normal atmospheric pressure.
The pump may not start up against pressure or vacuum during
switch-on. This also applies in operation following a brief power
failure. If a pump starts against pressure or vacuum, it may
block. This activates the thermal switch, and the pump
switches off.

Make sure that normal atmospheric pressure is present in the
lines during switch-on.
The life of the diaphragm is prolonged if the formation of conden-
sate is avoided. Therefore the following precautions should be
taken:

Run the pump for a few minutes to warm it up before handling
saturated or nearly saturated vapours.

KNF recommends: When transferring aggressive media, flush
the pump prior to switch-off (see chapter 8.2.1) to increase the
service life of the diaphragm.
Pump standstill
Vapors as media