Flowserve MEN - Manual (Page 31)

MEN USER INSTRUCTIONS ENGLISH 71576288 – 11-09
Page 31 of 36
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7 FAULTS; CAUSES AND REMEDIES
7.1 Faults on the pump
Insufficient flow rate
Irregular pump running
Driver overloaded
Mechanical seal leak
Equipment vibration
Excessive pump casing temperature
POSSIBLE CAUSES SOLUTIONS
x x x X Pump or suction pipe not completely filled - Check and complete filling
X X X Air bubbles in pipes - Check and desecrate the pipes
X X X Suction level too low - Check: the available NPSH > the required NPSH
- Reduce geometrical suction lift
- Reduce head losses in pipes and in fittings (diameter
increase and appropriate fitting positions)
- Check valves and strainers
- Check the immersion head of the suction valve
X X 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
X X Total manometric head system lower than
pump differential head
-Throttle at discharge valve or trim the impeller (contact our
local agent) CONSULT FLOWSERVE
X X X Pipes (valves, filter...) - Control, dismantle and clean
X X Insufficient flow rate - Check the suction and discharge pipes (valves, back
pressure)
X Worn wear-ring surfaces - Foresee pump mending. CONSULT FLOWSERVE
X X X X Seizure, jamming - CONSULT FLOWSERVE
X X X X Excessive strains on flanges - Check the flange connections and eliminate strains (pipe
positioning or elastic sleeves mounting)
X Defective gland packing on the shaft - Check and replace all the gland packing parts
- Mechanical seal: CONSULT FLOWSERVE
X X X X Defective motor bearings - CONSULT FLOWSERVE
X X Specific gravity or viscosity of liquid too high - Consult our local agent to analyze the problem
X Misalignment - Check the alignment of the pump and of its driver
X Foundations not sufficiently rigid - Check the setting of base plates: tightening, bad adjustment,
seal
Insufficient pressure
Pump looses prime after starting
POSSIBLE CAUSES SOLUTIONS
X X Presence of air - Check and de-aerate
x Suction pressure insufficient - Check: the available NPSH > the required
NPSH
X Mechanical defects - CONSULT FLOWSERVE
X Air leak in the suction pipe - Check suction pipe is airtight
X Restriction in suction pipe - Check diameter of suction pipe
X Suction level too low - Check the NPSH >NPSH
- Reduce geometrical suction lift
- Reduce head losses in pipes and in fittings
(diameter increase and appropriate fitting
positions)
- Check valves and strainers
- Check the immersion head of the suction valve
X Obstruction of suction pipe - Check condition of pipe
X Defective gland packing on the shaft - Check and replace all the gland packing.
- Mechanical seal: CONSULT FLOWSERVE
X Defective gasket - CONSULT FLOWSERVE