Operating instructions

11.2 Replacing the metering diaphragm
Third party spare parts for the pumps may lead to problems
when pumping.
– Use only original spare parts.
– Use the correct spare part kits. In case of doubt, refer to
the exploded views and ordering information contained
in the "Supplementary information CD for ProMinent
®
pump operating instructions".
Personnel:
n
Technical personnel
Requirements:
n If necessary take protective measures.
n Observe the safety data sheet for the feed chemical.
n Depressurise the system.
1. Drain the liquid end: Place the liquid end on its head and allow the
feed chemical to run out; flush out with a suitable medium; flush the
liquid end thoroughly when using hazardous feed chemicals!
2. With the pump running, move the stroke adjustment dial to the stop
at 0 % stroke length.
ð
The drive axle is now difficult to turn.
3. Switch off the pump.
4. Unscrew the hydraulic connectors on the discharge and suction
side.
5. Unscrew the diaphragm rupture sensor from the dosing head.
6. Remove the 6 screws on the dosing head.
7. Remove the dosing head.
8. Check the condition of the diaphragm rupture sensor - see
Ä “ Checking the condition of the diaphragm rupture sensor”
on page 59
.
9. Loosen the diaphragm from the drive axle with a gentle backwards
turn in the anti-clockwise direction.
10. Completely unscrew the diaphragm from the drive axle.
11. Tentatively screw the new diaphragm anticlockwise up to the stop
on the drive axle.
ð
The diaphragm now is now seated against the stop of the
thread while the diaphragm flap is within the tolerance range.
P_SI_0029
2
3
A
1
Fig. 43: Tolerance range of the flap on the backplate
1 Diaphragm
2 Backplate
Repairs
57