8.2 Start-up/subsequent start-up of DMH 251, 252 and
253
M
F
Fig. 24 Start-up of DMH 251, 252 and 253
Pos.
Components
1q
Dosing head screws
2
Dosing head
3b
Discharge valve
E
Degassing valve
F
Oil-filling screw with dipstick
L
Stroke-length adjustment knob
1l
Cover for stroke-length adjustment knob
M
Pressure relief valve
1. Connect the electrical power supply.
2. Depending on the installation, start the pump, where possible,
without counter-pressure.
See installation example for easy deaeration of the dosing head
in section
6. Installation
.
3. Set the stroke-length adjustment knob (L) to 0 %.
4. Let the pump run for approx. 5 minutes.
5. Check the oil level.
– Set the stroke-length adjustment knob (L) to 40 %.
– Let the pump run for approx. 10 minutes with a stroke-length
setting of 40 %.
– Switch off the pump, check the oil level and add oil, if
necessary.
– Refit the oil-filling screw (F).
6. Deaerate the piston flange.
– Set the stroke-length adjustment knob (L) to 15 %.
– Loosen the degassing valve (E) by one turn to the left.
– Let the pump run for approx. 5 minutes.
– Re-tighten the degassing valve (E).
The pump is now ready for operation.
Warning
Risk of injury caused by squirting oil!
Oil may squirt from the oil deaeration when the pump
is running. Do not completely unscrew the oil
deaeration screw.
Wear protective clothing (gloves and goggles) when
working on the dosing head, connections or lines!
Rod length of oil dipstick: 27 mm.
Note
Immersion depth to marking: approx. 5 mm.
Check the oil level at least every two weeks and add
oil, if necessary.
Only use original Grundfos gear oil!
Note
For product numbers, see "Service kit catalogue" on
www.grundfos.com
E
M
3b
1l
L
1q
2
Pump model
Version
DMH 251
Single/double
DMH 252, 10 bar
Single/double
DMH 252, 16 bar
Single/double
DMH 253
Single/double
After start-up
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 model
DMH 251, 10 bar
DMH 251, 16 bar
DMH 251, 25 bar
DMH 252
DMH 253
8.3 Start-up/subsequent start-up of DMH 254, 255 and
257
M
F
Fig. 25 Start-up of DMH 254, 255 and 257
Pos.
Components
1q
Dosing head screws
2
Dosing head
3b
Discharge valve
F
Oil-filling screw with dipstick
L
Stroke-length adjustment knob
1l
Cover for stroke-length adjustment knob
M
Pressure relief valve
1. Connect the electrical power supply.
2. Depending on the installation, start the pump, where possible,
without counter-pressure.
See installation example for easy deaeration of the dosing head
in section
6. Installation
.
3. Set the stroke-length adjustment knob (L) to 0 %.
4. Let the pump run for approx. 5 minutes.
5. Check the oil level.
– Set the stroke-length adjustment knob (L) to 40 %.
– Let the pump run for approx. 10 minutes with a stroke-length
setting of 40 %.
– Switch off the pump, check the oil level and add oil, if
necessary.
– Refit the oil-filling screw (F).
The pump is now ready for operation.
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
Torque
[Nm]
8-10
10-12
13-15
8-10
10-12
M
3b
1l
L
1q
2
29