Grundfos DMH 25X, Installation And Operating Instructions Manual

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10.6 Replacing the diaphragm and gear oil for dosing
head with single diaphragm (no diaphragm leakage
detection)
Warning
Wear protective clothing (gloves and goggles) when work-
ing on the dosing head, connections or lines!
The dosing diaphragm should be replaced with each gear
oil change.
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.
Note
Only use original Grundfos gear oil!
For product numbers, see "Service kit catalogue" on
www.grundfos.com
Pump model Version Description
DMH 251 Single/double
1,3 l white oil (Paraf-
fin 55 DAB7)
DMH 252, 10 bar Single/double
1,3 l white oil (Paraf-
fin 55 DAB7)
DMH 252, 16 bar Single/double 1,3 l DHG 68
DMH 253 Single/double 1,3 l DHG 68
DMH 254 Single 3,5 l DHG 68
DMH 254 Double 4,5 l DHG 68
DMH 255 Single 3,5 l DHG 68
DMH 255 Double 4,5 l DHG 68
DMH 257 Single 5,5 l DHG 68
DMH 257 Double 7,5 l DHG 68
Note
Collect the gear oil in a container and dispose of it correct-
ly.
10.6.1 Drain gear oil
1b
L
F
B
TM036472
Drain gear oil
Pos. Components
B Locking screw
1b Gasket
F Oil-filling screw with dipstick
L Stroke-length adjustment knob
1. Unscrew the locking screw (B) and collect the gear oil in a
container.
2. Screw the locking screw (B) and the new gasket (1b) back in
and tighten securely.
Caution
Risk of leaking oil and damage caused by oil loss!
For each oil change, a new flat gasket (1b) must be fitted!
10.6.2 Removing the dosing head
1. Close the suction and discharge lines and loosen the suction
and discharge valve connections.
2. Loosen the six dosing head screws (1q with 2q).
3. Remove the dosing head (2).
10.6.3 Replacing a single diaphragm (no diaphragm leakage
detection)
• Remove the diaphragm and fit a new diaphragm (Q) on the
suction side.
1q
Q
2
2q
TM036473
Replacing a single diaphragm
Pos. Components
1q Dosing head screw
2q Intermediate disk
2 Dosing head
Q Diaphragm
10.6.4 Fitting the dosing head
• Fit the dosing head and cross-tighten the dosing head screws
(1q with 2q) using a torque wrench.
Note
See section Start-up/shutdown for subsequent start-up!
Related information
8.1 Initial start-up/subsequent start-up
10.6.5 Filling with gear oil
Caution
Risk of leaking oil and damage caused by oil loss!
For each oil change, a new flat gasket (1b) must be fitted!
1. Check that the locking screw (B) is tightened.
2. Slacken and remove the oil-filling screw (F).
3. Set the stroke-length adjustment knob (L) to "0".
4. Slowly add the hydraulic oil through the oil-filling opening (F)
until the oil reaches the mark on the oil dipstick.
5. Wait 30 minutes.
6. Let the pump run for approx. 5 minutes with a stroke-length
setting of 0 %.
7. Let the pump run for approx. 10 minutes with a stroke-length
setting of 40 %.
37
English (GB)