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14.5 Replacing the diaphragm
14.5.1 Switching off the pump
1. While the pump is running, set the stroke-length adjustment
knob to 100 %.
2. Switch off the pump and disconnect it from the power supply.
3. Depressurise the system.
4. Take suitable steps to ensure that the returning dosing
medium is safely collected.
14.5.2 Replacing the diaphragm
1. Loosen the six dosing head screws.
2. Remove the dosing head.
3. Turn the fan blades until the diaphragm reaches the front dead
centre (the diaphragm detaches itself from the diaphragm
flange).
4. Unscrew the diaphragm by manually turning it counter-
clockwise.
5. Check the parts and replace by new ones, if necessary.
6. Screw in the new diaphragm completely. Then turn it back until
the holes in the diaphragm and the flange coincide.
7. Turn the fan blades until the diaphragm reaches the bottom
dead centre (the diaphragm is pulled onto the diaphragm
flange).
8. Refit the dosing head carefully and cross-tighten the screws.
Maximum torque: 6 Nm.
9. Deaerate and start the dosing pump.
Caution
Adjust the stroke length only while the pump is
running!
Caution
For transport or cleaning, the venting cartridge
must be closed.
Note
If possible, rinse the dosing head, e.g. by
supplying it with water.
Caution
Before start-up, open the venting cartridge
(pull cap approx. 5 mm).
Caution
After initial start-up and after each time the
diaphragm is changed, tighten the dosing head
screws.
After approximately 6-10 operating hours or
two days, cross-tighten the dosing head screws
using a torque wrench.
Maximum torque: 6 Nm.
Summary of Contents for DMX 115-3
Page 1: ...DMX 221 GRUNDFOS ALLDOS INSTRUCTIONS Installation and operating instructions ...
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