______________________________________________________________________________
DESMI Pumping Technology A/S
15
Tagholm 1
9400 Nørresundby – Denmark
Tel: +45 96 32 81 11 Fax: +45 98 17 54 99
E-mail:
FAULT
CAUSE
REMEDY
The pump does not
prime
1. The pump is not filled with liquid
2. Leaking non-return valve in
pump
3. Wrong direction of rotation
4. Air is drawn in because of too
little liquid or leaking suction line
5. Liquid lock in outlet line
6. Temperature of liquid too high
7. Air cannot escape on pressure
side
Fill pump casing with liquid
Remove foreign body in
valve/Remove any coating
on mating faces
Change direction of
rotation
Lower suction pipe/
Tighten suction line
Change the pressure line
so that the air can pass out
freely
Replace liquid in pump
casing/Wrong dimen-
sioning/Contact DESMI
Ventilate the system
The pump has no or
too low capacity
1. Wrong direction of rotation
2. Piping system choked
3. The pump is choked
4. Suction line leaks
Pump takes air
5. Suction lift too high
6. Pump and piping system wrongly
dimensioned
Change direction of
rotation to clockwise when
viewed from shaft end (the
direction of the arrow)
Clean or replace
Clean the pump
Find the leakage/repair the
fault, non-return valve not
submerged
Check data sheet Q/H
curve and NPSH or
contact DESMI
As 5
The pump uses too
much power
1.
Counter-pressure too low
2.
The liquid is heavier than
water
3.
Foreign body in pump
4.
Electric motor is running on 2
phases
Insert orifice plate or
check valve/Contact
DESMI
Contact DESMI
Dismantle the pump,
remove the cause
Check fuses, cable
connection, and cable
The pump makes
noise
1. Cavitation in pump
Suction lift too high/
Suction line wrongly
dimensioned/Liquid
temperature too high