14.2 Replacing the Diaphragm
n
If necessary take protective measures.
n
Adhere to the material safety data sheet for the feed chemical.
n
Prevent the escape of feed chemical.
n
Ensure that the system is at atmospheric pressure.
1.
Empty the liquid end (turn the liquid end upside down 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.
Set up
‘Service
è
Diaphragm replacement
è
To replacement position’
ð
The pump moves the diaphragm away from the backplate.
Now leave the pump connected to the mains/
power supply so that this state is maintained.
3.
Unscrew the hydraulic connectors on the discharge and suction
side.
4.
With types with coarse/fine bleed valve: Firstly remove the coarse/
fine bleed valve (grip), then lift off the cover of the liquid end with a
screw driver.
P_G_0050_SW
1
2
3
4
5
6
Fig. 38: Partially exploded view of liquid end
1
Screws
2
Dosing head
3
Diaphragm
4
Backplate
5
Safety diaphragm
6
Pump housing
5.
Remove the screws (1).
6.
Remove the dosing head (2) plus screws (1) from the pump - see
figure
7.
Loosen the diaphragm (3) from the drive axle with a gentle back‐
wards turn in an anticlockwise direction.
8.
Unscrew the diaphragm (3) completely from the drive axle.
9.
Remove the backplate (4) from the pump housing (6).
10.
Check the condition of the safety diaphragm (5) and replace if nec‐
essary.
11.
Push the safety diaphragm (5) onto the drive axle only until it lies
flush with the pump housing (6) and no further!
Repairs
70
