Dmh 251, 252 And; Start-Up / Subsequent Start-Up Of Dmh 251, 252 And 253 - Grundfos DMH 251 Installation And Operating Instructions Manual

11.1.3 Filling the dosing head for the initial start-up for
systems without flooded suction
Warning
When dosing dangerous media, observe the
corresponding safety precautions!
Wear protective clothing (gloves and goggles)
when working on the dosing head, connections
or lines!
As assisting suction for systems without flooded suction, you can
fill the dosing head with dosing medium before the initial start-up:
1. Unscrew the discharge valve (3b).
2. Add the dosing medium to the dosing head (2).
3. Screw the discharge valve (3b) back in.
Observe the flow direction of the discharge valve
Note
(indicated by an arrow on the valve)!
11.2 Start-up / subsequent start-up of DMH 251, 252
and 253
M F
Fig. 26 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 .
9. 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.
E M
3b
1l
L
1q
2
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.
Note
Only use original Grundfos Alldos gear oil!
For product number, see service instructions.
Pump type
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 type
DMH 251, 10 bar
DMH 251, 16 bar
DMH 251, 25 bar
DMH 252
DMH 253
11.3 Start-up / subsequent start-up of DMH 254, 255
and 257
M F
Fig. 27 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
Version 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
25