Problem Solving
Page 10
11. Fault diagnosis
11.1. Pump Unit Problems:
Symptom
Possible Causes
Remedy
Lack of Prime
Fill the pump and its suction pipe completely with the
liquid being handled, Bleed the pump and piping to remove air.
Pump Drive is Interrupted or Speed is Too Low
Check drive coupling and motor connection
Discharge Head too High
Check discharge line for blockages. Check that valves and other
safety devices are working correctly, Check that the size and design
of the delivery line meets the specification of the pump
Suction Lift Too High
Check suction line for blockages. Check that the size and design of
the suction line meets the specification of the pump
Wrong Direction of Rotation
Check and correct as detailed in section 5.7
Filter Blockage
Check filter elements, clean or replace.
Fluid or Air Leakage
Check for leaks in the pipe work and connection flanges,
Replace worn gaskets & seals as appropriate
Suction Pipe not Fully Submerged
Check fluid reserve level or pipe work design
Speed is Too Low.
Check drive speed is appropriate for the duty
Gas or Vapour in the system.
Bleed the pump and piping to remove the air from the system
Worn Pump Internal Parts.
Contact our Sales Engineers
Worn Gaskets or Seals
Replace or Contact our Sales Engineers
Obstruction in the Suction line
Check and clear suction line of any blockages
Suction pipe not fully submerged
Check fluid reserve level or pipe work design
Pumped Fluid Contains Air
Check the system design - rid the fluid of air
Suction Lift Too High
Check suction line for blockages. Check that the size and design of
the suction line meets the specification of the pump
Discharge Head Too High
Check discharge line for blockages. Check that valves and other
safety devices are working correctly, Check that the size and design
of the delivery line meets the specification of the pump
Speed Too High
Check drive speed is appropriate for the duty
Pump Housing Distorted
Check the connection to mounting flange or base foundation and
pipe work comply with sections 5.5 and 5.6
Pump Drive Shaft Misalignment
Check drive shaft connection is correctly aligned (see appendix 1)
Gas or Vapour in the system.
Check the tightness of the pipe work fasteners
Bleed the pump and piping to remove the air from the system
Pump Drive Shaft Misalignment
Check drive shaft connection is correctly aligned (see appendix 1)
Non Rigid Foundation
Check foundation design and revise as appropriate
Worn Pump Internal Parts.
Contact our Sales Engineers
Worn Gaskets or Seals
Replace or Contact our Sales Engineers
Suction Lift Too High
Check suction line for blockages. Check that the size and design of
the suction line meets the specification of the pump
Debris in the Fluid
Check filters for blockage,
Check pump bores and clean away any debris
Check for damage to the rotor teeth - Contact our sales engineers
Elimination of Internal Rotor Clearance
This is indicative of bearing wear - Contact our sales engineers.
Closed or Sticking Valve
Check all valves are correctly set and working.
Excessive Fluid or Pump
Temperature
Not Enough or No Liquid is
Delivered
Pump Overloads the Drive
Cavitation (excessive noise)
Discharge Pressure is Too Low
Excessive Vibration or Noise
Any further information or clarification required may be obtained by contacting our sales office,
Please see contact details at the back of this booklet.
When contacting our sales office please have the following information available:
•
Nameplate data (complete)
•
Type and extent of the problem encountered
•
The time and the circumstances the problem occurred
•
A possible cause
