24
DEPA
®
Air Operated Diaphragm Pumps
4.3
Flow control
The pump flow can be regulated via the fed
air pressure and the air quantity. We rec-
ommend an air flow dependent regulation,
in order to rule out fluctuations in pumping
pressure. The air pressure must in this case
be considerably higher than the pumping
pressure. It is recommended to run the pump
with a stroke frequency as low as possible,
in order to save wear items, e.g. diaphragms,
ball valves and air control valve and to protect
the environment.
4.4
Switching off the pump
To shut-off the pump reduce the air flow to the
pump by means of the valve. The pump will
stop immediately.
Warning!
If the pumped product is of ag-
gressive nature the pump must
be thoroughly flushed or cleaned
after use.
Observe the notes on cleaning.
4.5
What to do in events of emergency
In the event of an emergency, the pump must
be switched off immediately and, if necessary,
secured against being switched on again.
4.6
Remote operation indicator
Operation of the pump can be electronically
monitored by means of a remote operation
indicator.
4.7
Diaphragm monitoring -
conductive
With a defective diaphragm product will en-
ter into the air chamber, where it is detected
by the integrated sensor. When pumping
conductive product the conductivity meas-
urement will measure a current flow between
both electrodes.
The evaluation unit supplies the sensor with
voltage and from a certain amperage (<1mA)
it switches a relay, which in turn switches the
pump off or triggers an alarm signal.
Note:
The product must have a
minimum conductivity value of
>5µS.
4.8
Diaphragm monitoring -
capacitive
When pumping non-conductive product
diaphragm monitoring requires the use of a
capacitive sensor system.
4.9
Cleaning pumps for food
applications (CIP = Clean In Place)
The pumps can be cleaned manually after
dismantling or in place (CIP). Consult the
pump supplier for special application related
cleaning procedures.
Here an example for CIP-cleaning:
■
To clean the inside, the pump must be
flushed with cold water during operation.
■
Flush with approx. 2.5% caustic soda
solution at 70 - 80°C for approx. 20 - 30
minutes.
■
Finally flush again with cold, clear water.
Warning!
During all CIP cleaning
processes the DEPA® Air
Operated Diaphragm Pump
must be running. Otherwise the
diaphragm may be excessively
stretched and prematurely
damaged.
Warning!
Reassemble clamp bands or
mounting flanges after cleaning,
retighten if necessary!
