20
14. Maintenance
14.1 General notes
14.2 Changing the gear grease
To ensure trouble-free operation, it is recommended to have the
gear grease changed after five years or after 20,000 operating
hours.
14.2.1 Cleaning and maintenance intervals
Clean the diaphragm and valves, or replace if necessary
(with stainless-steel valves: inner valve parts):
• regularly every 12 months or after 4,000 operating hours.
When operating with a counter-pressure of 16 bar, every six
months or after 2,000 operating hours,
or
• in case of malfunction.
14.3 Cleaning the suction and discharge valves
If the pump looses capacity, clean the suction and discharge
valves as follows:
1. Unscrew the valve.
– DN 20
Unscrew the screw part resp. valve seat with round pliers.
– DN 8
Press out the valve cartridge and remove the valve seat
from the ball cage.
2. Clean all parts. Replace faulty parts by new ones.
3. Re-assemble the valve.
4. Replace the O-rings by new ones. Refit the valve. Observe the
direction arrow on the valve.
Fig. 22
Exploded view of the valves
14.4 Maintenance of the relief valve
14.4.1 Cleaning and maintenance intervals
Clean the relief valve, and replace the diaphragm, if necessary.
• At least every 12 months or after 8,000 operating hours.
• In the event of a fault.
14.4.2 Replacing the diaphragm of the relief valve
1. Switch off the pump and disconnect it from the power supply.
2. Make it impossible for a return flow or overpressure to occur.
3. Loosen the four screws on the top part of the relief valve.
4. Remove the top part of the relief valve.
5. Remove the diaphragm.
6. Insert a new diaphragm.
7. Refit the top part of the relief valve and cross-tighten the
screws.
Maximum torque: 6 Nm.
8. Start up the dosing system.
9. Tighten the screws on the top part of the relief valve after
48 operating hours.
Maximum torque: 6 Nm.
Warning
When dosing dangerous media, observe the
corresponding safety precautions!
Risk of chemical burns!
Wear protective clothing (gloves and goggles)
when working on the dosing head, connections
or lines!
Do not allow any chemicals to leak from the
pump. Collect and dispose of all chemicals
correctly!
Warning
The pump housing must only be opened by
personnel authorised by Grundfos Alldos!
Repairs must only be carried out by authorised
and qualified personnel!
Switch off the pump and disconnect it from the
power supply before carrying out maintenance
work and repairs!
Caution
For transport or cleaning, the venting cartridge
must be closed.
Before start-up, open the venting cartridge
(pull cap approx. 5 mm).
Warning
The gear grease must only be changed by
authorised and qualified personnel.
For this purpose, send the pump to Grundfos
Alldos or an authorised service workshop.
Caution
If possible, rinse the dosing head, e.g. by
supplying it with water.
TM
0
3
2
644
4
705
/ TM
0
3
2
6
1
0
4
605
Caution
The O-rings must be correctly placed in the
specified groove.
Observe the flow direction (indicated by an arrow
on the valve)!
Optional
DN 20
DN 8
Summary of Contents for DMX 115-3
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