Start-Up/Shutdown; Initial Start-Up/Subsequent Start-Up - Grundfos DMH 25X Installation And Operating Instructions Manual

8. Start-up/shutdown

8.1 Initial start-up/subsequent start-up

Warning
When dosing dangerous media, observe the correspond-
ing safety precautions!
Wear protective clothing (gloves and goggles) when work-
ing on the dosing head, connections or lines!
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.
The pump housing must only be opened by personnel au-
thorised by Grundfos!
Repairs must only be carried out by authorised and quali-
fied personnel!
Observe the flow direction of valves (indicated by an ar-
row on the valve)!
Caution
Only tighten plastic valves by hand.
8.1.1 Checks before start-up
• Check that the rated voltage stated on the pump nameplate
corresponds to the local conditions!
• Check that all connections are secure and tighten, if necessary.
• Check that the dosing head screws are tightened with the
specified torque and tighten, if necessary.
• Check that all electrical connections are correct.
• 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
DMH 254
DMH 255
DMH 257
8.1.2 Oil filling
The pump is factory-checked, and the oil is drained for
shipping purposes. Before start-up, add the special oil
supplied with the pump.
Note The piston flange is filled with oil for easy start-up. The
stroke-length adjustment knob must only be adjusted if the
gear oil has been added, otherwise the oil will leak from
the piston flange.
1. Slacken and remove the oil-filling screw (F).
2. Slowly add the hydraulic oil supplied with the pump through the
oil-filling opening (F) until the oil reaches the mark on the oil
dipstick.
3. Set the stroke-length adjustment knob (L) to "0".
30
8.1.3 Filling the dosing head for the initial start-up for systems
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.
8.2 Start-up/subsequent start-up of DMH 251, 252 and
253
Torque
[Nm]
Start-up of DMH 251, 252 and 253
8-10
10-12
Pos.
13-15
1q
8-10
2
10-12
3b
50-54
E
50-54
F
50-54
L
1l
M
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 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
• Switch off the pump, check the oil level and add oil, if
• 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.
without flooded suction
Warning
When dosing dangerous media, observe the correspond-
ing safety precautions!
Wear protective clothing (gloves and goggles) when work-
ing on the dosing head, connections or lines!
Observe the flow direction of the discharge valve (indi-
Note
cated by an arrow on the valve)!
M F
1l
L
Components
Dosing head screws
Dosing head
Discharge valve
Degassing valve
Oil-filling screw with dipstick
Stroke-length adjustment knob
Cover for stroke-length adjustment knob
Pressure relief valve
setting of 40 %.
necessary.
E M
3b
1q
2