Fitting The Dosing Head; Filling With Gear Oil; Replacing The Diaphragm For Dosing Head With Double Diaphragm; Replacing A Double Diaphragm - Grundfos DMH 25X Manual De Instrucciones

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.
See section 8. Start-up/shutdown
Note
start-up!

10.6.5 Filling with gear oil

Risk of leaking oil and damage caused by oil loss!
Caution
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 %.
10.6.6 Checking the oil level
1. Switch off the pump, check the oil level and add oil, if
necessary.
2. Refit the oil-filling screw (F).
After initial start-up and after each time the
diaphragm is changed, tighten the dosing head
screws.
Caution
After approximately 6-10 operating hours or two
days, cross-tighten the dosing head screws using a
torque wrench.
Torques
Pump type
DMH 251, 10 bar
DMH 251, 16 bar
DMH 251, 25 bar
DMH 252
DMH 253
DMH 254
DMH 255
DMH 257
10.7 Replacing the diaphragm for dosing head with
double diaphragm
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
10.7.1 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).

10.7.2 Replacing a double diaphragm

1. Clean the intermediate disk (3q), sealing rings (4q) and
covering rings (5q). After a diaphragm breakage, replace the
parts by new ones.
for subsequent
2. Remove both clamping sleeves (6q) slightly using pliers. After
a diaphragm breakage, replace the parts by new ones.
3. Measure the outer wall thickness of both new diaphragms (Q1
and Q2): s1
Fig. 39 Installation of diaphragm
1) The shape of the diaphragm varies depending on pump type.
Pos.
1q
2q
2
Q1/Q2
Torque
3q - 5q
[Nm]
8-10
10-12
Caution
13-15
8-10
10-12
4. Fit both new diaphragms (Q1 and Q2) and the parts (3q - 5q)
50-54
in the correct order, as is shown in the diagrams (the clamping
sleeves (6q) are used for centring purposes).
50-54
50-54
Fig. 40 Diaphragm on dosing-head side
Pos.
S
Q1
Q2
3q
4q
5q
6q
< s2 .
(Q1) (Q2)
s < s
1 2
2q
1q
2
Q1 3q - 5q Q2
1)
Components
Dosing head screw
Intermediate disk
Dosing head
See fig. 40
Observe correct installation of diaphragms (Q1 and
Q2)! See fig. 40.
Fit the thinner diaphragm (Q1) on the dosing side
and the thicker diaphragm (Q2) on the oil side/pump
side!
S
6q
3q
2 Q1 5q 4q 3q 4q 5q
Components
Contact pressure gauge (installation position)
Diaphragm on dosing-head side
Diaphragm on oil side/pump side
Intermediate disk
Sealing rings
Covering rings
Clamping sleeves
Q2
33