Flowserve VF - Manual (Page 27)

VF USER INSTRUCTIONS ENGLISH 71561233 - 11/09
Page 27 de 32
7 FAULTS; CAUSES AND REMEDIES
Insufficient flow rate
Irregular pump running
Driver overloaded
Mechanical seal leak
Equipment vibration
Excessive pump casing temperature
POSSIBLE CAUSES SOLUTIONS
Air bubbles in pipes - Check and deaerate the pipes
Suction level too low - Check the available NPSH > the required NPSH
- Check valves and strainers
- Check the immersion head of the suction valve
Wrong rotation - Reverse 2 phases on motor terminal boxes
The motor is running on 2 phases only - Check and control the motor electrical power supply
Motor running too low - Check the connection in the terminal box according to the
voltage
Total manometric head system higher than pump
differential head - Check the discharge head
- Check the head losses in discharge pipes (partly closed
valve, foreign particles, back pressure too high)
- Modify the installation or change the pump set
Total manometric head system lower than pump
differential head -Throttle at discharge valve or trim the impeller (contact our
local agent)
Pipes (valves, filter...) - Control, dismantle and clean
Insufficient flow rate - Check the discharge pipe (valves, back pressure)
Worn wear-ring surfaces - Foresee pump mending: CONSULT FLOWSERVE
Seizure, jamming - CONSULT FLOWSERVE
Excessive strains on flanges - Check the flange connections and eliminate strains (pipe
positionning or elastic sleeves mounting)
Defective gland packing on the shaft - Check and replace all the gland packings parts
- Mechanical seal: CONSULT FLOWSERVE
Defective motor bearings - CONSULT FLOWSERVE
Specific gravity or viscosity of liquid too high - Consult our local agent to analyse the problem
Misalignment - Check the alignment of the pump and of its driver
Foundations not sufficiently rigid - Check the setting of baseplates: tightening, bad
adjustment, seal
Insufficient pressure
Pump looses prime after starting
POSSIBLE CAUSES SOLUTIONS
Rotation speed too low (check the driver) - Check the connection in the terminal box according to the
voltage
Mechanical defects - CONSULT FLOWSERVE
Suction level too low - Check the available NPSH > the required NPSH
- Reduce geometrical suction lift (diameter increase and
appropriate fitting positions)
- Check valves and strainers
- Check the immersion head of the suction valve
Defective gasket - CONSULT FLOWSERVE