Grundfos DMH 28 Serie Montage- Und Betriebsanleitung Seite 26

1. Loosen the dosing head deaeration screw (V) by approx. 1
turn.
2. Fit the hose (1j) supplied with the pump onto the deaeration
nipple (I).
3. Using the syringe (Z) supplied with the pump, carefully draw
the dosing medium until there is some liquid in the hose.
4. Tighten the deaeration screw (V).
5. Remove the hose (1j) and the syringe (Z).
6. Set the stroke-length adjustment knob to 70 % and let the
pump run for approx. 5 minutes.
7. Switch off the pump, check the oil level and add oil, if
necessary.
8. Refit the oil filling screw (F).
9. If already dosing, the pump is now ready for operation. If the
pump is not dosing, deaerate the piston flange.
Deaerating the piston flange
Y
E
1e
V
Fig. 26 Deaerating the piston flange
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
V Deaeration screw
I Hose nipple (connection for J)
J Deaeration hose (not supplied with the pump)
1m Cover for pressure relief valve
2m Adjusting screw
3m Pressure relief valve
4m Spring
E Degassing valve (cartridge)
1e Adjusting screw
Y Holes
1. Unscrew the cover for the pressure relief valve (1m).
2. Measure the adjustment depth (h) of the adjusting screw (2m).
3. Unscrew the adjusting screw (2m).
4. Remove the pressure relief valve (3m) with spring (4m).
5. Unscrew the whole degassing valve (cartridge) (E) using a
fork wrench, size 14.
26
1m
h
2m
3m
4m
Y
Do not turn the inner slotted screw (adjusting screw
Caution
(1e)), as this changes the degassing valve setting.
6. Connect the electrical power supply.
7. Let the pump run for approx. 5 minutes at a stroke setting of 0
% until oil (without bubbles) appears around the holes (Y).
Add oil, if necessary.
8. Switch off the pump and screw in the degassing valve (E) with
front side O-ring.
9. Refit the pressure relief valve (M/2m, 3m, 4m) in reverse order.
Set the adjusting screw to the depth (h) already measured.
10. Set the stroke-length adjustment knob to 70 % and let the
pump run for approx. 5 minutes.
The pump is now ready for operation.
Checking the degassing valve (cartridge)
The degassing valve (E) only operates with the
spring (5e), ball (6e) and correct position of the
Note
adjusting screw (7e).
Check the setting of the degassing cartridge when the pump is
switched off:
• Fully tighten the adjusting screw (7e) and then loosen by
approx. 1/4 turn!
Fig. 27 Degassing valve
Pos. Components
5e Spring
6e Ball
7e Adjusting screw
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 gear oil!
For product numbers, see "Service kit catalogue" on
www.grundfos.com
Pump type Version
DMH 280 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 280
7e
5e
6e
Description
1.3 l DHG 68
Torque
[Nm]
55-60