Replacing The Diaphragm - ProMinent Sigma 3 Basic Operating Instructions Manual

Carrying out repairs
12.2

Replacing the diaphragm

58
Third-party spare parts for the pumps may lead to prob‐
lems when pumping.
– Only use original spare parts.
Use the correct spare parts kits. In the event of
–
doubt, refer to the exploded views and ordering
information in the appendix.
Personnel:
n
Requirements:
If necessary take protective measures.
n
Adhere to the material safety data sheet for the feed chemical.
n
Ensure that the system is at atmospheric pressure.
n
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
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 an 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.
3
A
Fig. 23: Tolerance range of the flap on the backplate
1 Diaphragm
2 Backplate
3 Flap
A Tolerance range
Technical personnel
P_SI_0029
Ä '
1
2