40
A.0500.501 – IM-TGGS/05.01 EN (03/2013)
Symptom
Cause
Remedy
No flow
Pump not priming
Suction lift too high
1
•
Reduce difference between
pump and suction tank level.
•
Increase suction pipe diameter.
•
Reduce length and simplify suction pipe (use as
few elbows and other fittings as possible).
Also see section 3.18 Installation.
Air leak in suction line
2
•
Repair leak.
Very low viscosity
3
•
Increase pump speed and reduce axial clearance
(see section 3.21 Maintenance instructions).
Suction strainer or filter clogged
4
•
Clear suction strainer or filter.
Pump casing incorrectly installed
after repair
5
•
Install pump casing correctly.
See section 3.18 Installation.
Wrong direction of rotation of motor
6
•
For 3-phase drivers change 2 connections.
•
Change suction and discharge opening.
(
Attention!
Check the location of the safety relief
valve).
Pump stalls or
irregular flow
Liquid level in suction tank falls too low
7
•
Correct liquid supply
•
Provide a level switch
Output too high
8
•
Reduce pump speed/or install a smaller pump.
•
Install by-pass line with check-valve.
Air sucking
9
•
Repair leak in suction line.
•
Check or replace shaft seal.
•
Check/provide quench on shaft seal.
•
Connect plug Bb to the pump discharge in order
to increase the pressure in the sealing box.
Cavitation
10
•
Reduce difference between pump and suction
tank level.
•
Increase suction pipe diameter.
•
Reduce length and simplify suction pipe (use as
few elbows and other fittings as possible).
Also see chapter 3.18 Installation.
Liquid vaporises in pump
(e.g. by heating up)
11
•
Check temperature.
•
Check vapour pressure of liquid.
•
Reduce pump speed. If necessary install a larger
pump.
Not enough capacity Pump speed too low
12
•
Increase pump speed.
Attention!
Do not exceed
maximum speed and check NPSHr.
Air sucking
13
•
Repair leak in suction line.
•
Check or replace shaft seal.
•
Check/provide a quench in the shaft seal.
•
Connect plug Bb to the pump discharge in order
to increase the pressure in the sealing box.
Cavitation
14
•
Reduce difference between pump and suction
tank level.
•
Increase suction pipe diameter.
•
Reduce length and simplify suction pipe (use as
few elbows and other fittings as possible).
Also see section 3.18 Installation.
Back pressure too high
15
•
Check discharge pipe.
•
Increase pipe diameter.
•
Reduce working pressure.
•
Check accessories (filter, heat exchanger, etc.).
Safety relief valve set too low
16
•
Correct pressure setting.
3.20 Trouble shooting
