Checking The Oil Level; Cleaning The Suction And Discharge Valves - Grundfos DMH 28 Serie Montage- Und Betriebsanleitung

10.4 Checking the oil level

Check the oil level at least every two weeks and add
Caution
oil, if necessary.
Rod length of oil dipstick:
DMH 280-281: 27 mm.
Note
DMH 283-288: 35 mm.
Immersion depth to marking: approx. 5 mm.

10.5 Cleaning the suction and discharge valves

Warning
Wear protective clothing (gloves and goggles) when
working on the dosing head, connections or lines!
Before removing the dosing head, valves and lines,
empty any remaining medium in the dosing head into
a drip tray by carefully unscrewing the suction valve.
DN 4 valve
• Screwed connection 3/8"
• Stainless steel
• Spring-loaded.
DN 8 valve
• Screwed connection 5/8"
• Stainless steel
• Spring-loaded.
DN 20 valve
• Screwed connection 1 1/4"
• Stainless steel
• Spring-loaded (optional).
Clean the suction and discharge valves as follows:
1. Unscrew the valves.
2. Unscrew the screw parts and valve set using round pliers.
3. Dismantle the inner part (seat, O-ring, balls, ball cages and, if
present, spring).
4. Clean all parts. Replace faulty parts by new ones.
5. Re-assemble the valve.
6. Replace the O-rings by new ones. Refit the valve.
Fig. 37 Stainless steel DN 4 valve, spring-loaded
32
Fig. 38 Stainless-steel DN 8 valve, spring-loaded
Fig. 39 Stainless-steel DN 20 valve
The O-rings must be correctly placed in the specified
groove.
Caution
Observe the flow direction (indicated by an arrow on
the valve)!
Optional
(DMH 283, 285)