Detection) - Grundfos DMH 25 Série Notice D'installation Et De Fonctionnement

Suction side
1)
Fig. 36 DN 32 valve, suction side and discharge side
The O-rings must be correctly placed in the specified
groove.
Caution
Observe the flow direction (indicated by an arrow on
the valve)!
Only tighten plastic valves by hand.
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
working 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.
Only use original Grundfos gear oil!
Note
For product numbers, see "Service kit catalogue" on
www.grundfos.com
Pump type Version
DMH 251 Single/double
DMH 252, 10 bar Single/double
DMH 252, 16 bar Single/double
DMH 253 Single/double
DMH 254 Single
DMH 254 Double
DMH 255 Single
DMH 255 Double
DMH 257 Single
DMH 257 Double
Collect the gear oil in a container and dispose of it
Note
correctly.
32
Discharge side
2)
Description
1.3 l white oil
(Paraffin 55 DAB7)
1.3 l white oil
(Paraffin 55 DAB7)
1.3 l DHG 68
1.3 l DHG 68
3.5 l DHG 68
4.5 l DHG 68
3.5 l DHG 68
4.5 l DHG 68
5.5 l DHG 68
7.5 l DHG 68
10.6.1 Drain gear oil
Fig. 37 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.
Risk of leaking oil and damage caused by oil loss!
Caution
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. See fig. 38.
2q
1q
2
Fig. 38 Replacing a single diaphragm
Pos. Components
1q Dosing head screw
2q Intermediate disk
2 Dosing head
Q Diaphragm
F
L
1b
B
Q