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PUMP TROUBLESHOOTING
NOTICE:
Maintenance shall be performed by qualified technicians only,
following the appropriate procedures and warnings as presented in this manual.
SYMPTOM
PROBABLE CAUSE
Pump Not Priming
1. Pump not wetted.
2. Suction valve closed.
3. Air leaks in the suction line.
4. Strainer clogged.
5. Suction line or valves clogged or too restrictive.
6. Wrong rotation on motor.
7. Broken drive train.
8. Pump vapor-locked.
9. Pump speed too low for priming.
10. Worn Vanes.
Reduced Capacity
1. Suction valves not fully open.
2. Air leaks in the suction line.
3. Excessive restriction in the suction line (i.e.: undersized piping, too many elbows &
fittings, clogged strainer, etc.).
4. Damaged or worn parts.
5. Excessive restriction in discharge line causing partial flow through the relief valve.
6. Relief Valve worn, set too low, or not seating properly.
7. Vanes installed incorrectly (see "Vane Replacement").
Noise
1. Excessive vacuum on the pump due to:
a. Undersized or restricted fittings in the suction line.
b. Pump speed too fast for the viscosity or volatility of the liquid.
c. Pump too far from fluid source.
2. Running the pump for extended periods with a closed discharge line.
3. Misalignment of the pump.
4. Baseplate not securely mounted.
5. Sleeve Bearings (bushings) worn or damaged.
6. Vibration from improperly anchored piping.
7. Bent shaft, or drive coupling misaligned.
8. Excessively worn rotor.
9. Malfunctioning valve in the system.
10. Insufficient oil in the gear reducer.
11. Damaged vanes (see following category).
Damaged Vanes
1. Foreign objects entering the pump.
2. Running the pump dry for extended periods of time.
3. Cavitation.
4. Viscosity too high for the vanes and /or the pump speed.
5. Incompatibility with the liquids pumped.
6. Excessive heat.
7. Worn or bent push rods, or worn push rod holes.
8. Settled or solidified material in the pump at start-up.
9. Hydraulic hammer - pressure spikes.
10. Vanes installed incorrectly (see "Vane Replacement”).
Broken Shaft
1. Foreign objects entering the pump.
2. Viscosity too high for the pump speed.
3. Relief valve not opening.
4. Hydraulic hammer - pressure spikes.
5. Pump/driver misalignment.
6. Overtightened V-belts, if equipped.
7. Excessively worn vanes or vane slots.
8. Settled or solidified material in the pump at start-up.
