English
16
Wilo AG 09/2005
5.3.1 Priming of a flooded pump
Close the discharge valve; fill the pump by ope-
ning the suction valve. Let air escape by removing
the plug located on the pipework.
The discharge pipe is headed and there is a by-
pass valve on the check valve, open slightly the
discharge valve and the by-pass of the check
valve.
When the pump is totally free of air bubbles,
replace the plugs.
5.3.2 Priming of a sump suction pump
* With foot valve:
Fill suction pipe and casing with liquid from an
independent source (pressure 1 to 2 bars).
Let air escape by removing the plugs located on
the pipework.
When the pump is totally free of air bubbles,
replace the plugs.
* Without foot valve:
Priming may be accomplished by means of venting
system.
5.4
Starting the pump
5.4.1 Bring controls and preparation before the first
starting and after each service call
Necessarily:
• Check the tightening of the different plugs.
• Check that the gland lightly tightens the packing
rings.
Install all protection systems and more particu-
larly the coupling guard and the shield grid
(reference [7450]) of the bearing.
• Open all suction valves (if existing).
• Close the outlet valve and the bypass valve.
• Ensure inlet pipe and pump casing are completely
full of liquid.
5.4.2 First pump start-up
• Start motor and check outlet pressure.
• If pressure is satisfactory, slowly OPEN outlet
valve.
• Do not run the pump with the outlet valve closed
for a period longer than 30 seconds.
• If NO pressure, or LOW pressure, STOP the pump.
Refer to faultfinding chart for fault diagnosis.
• The pump should run smoothly and without vibra-
tion.
• The pump must never run at a capacity of less than
40 % of that at the best efficiency.
Never remove a plug when the pump is running.
5.5
Running the pump
5.5.1 Venting the pump
Vent the pump to enable all trapped air to
escape taking due care with hot or hazardous
liquids.
Under normal operating conditions, after the
pump has been fully primed and vented, it
should be unnecessary to re-vent the pump.
5.5.2 Pump fitted with a stuffing box
If the pump has a packed gland there must be
some leakage from the gland. Gland nuts should
initially be finger tight only. Leakage should take
place soon after the stuffing box is pressurized. If
no leakage takes place the packing will begin to
overheat. If overheating takes place the pump
should be stopped and allowed to cool before
being restarted.
When the pump is restarted it should be checked
to ensure leakage is taking place at the packed
gland.
Priming of a flooded suction pump
Priming of a suction pump configuration
with foot valve
Foot valves are not recommended when
the pumped liquid has suspended solid
particles. They may lodge between foot
valve seat and shutter.
NOTE:
Risk of seal ring overheating.
Check the direction of rotation of the
motor. Refer to the rotation arrow of the
pump.
Suction valves must be fully open when
pump is running. Never run the pump
dry, it will cause damage.
CAUTION!
CAUTION!
