101-C00 Page 16/20
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. Worn
vanes
3. Suction valve closed.
4. Air leaks in the suction line.
5. Strainer
clogged.
6. Suction line or valves clogged or too restrictive.
7. Pump
vapor-locked.
8. Pump speed too low for priming.
9. Relief valve partially open, worn or not seating properly.
Reduced Capacity
1. Pump speed too low.
2. Suction valves not fully open.
3. Air leaks in the suction line.
4. Excessive restriction in the suction line (undersized piping, too many elbows & fittings, clogged
strainer, etc.).
5. Damaged or worn parts.
6. Excessive restriction in discharge line causing partial flow through the relief valve.
7. Relief Valve worn, set too low, or not seating properly.
8. 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. Pump not securely mounted.
4. Bearings worn or damaged.
5. Vibration from improperly anchored piping.
6. Bent shaft, or drive coupling misaligned.
7. Excessively
worn
rotor.
8. Malfunctioning valve in the system.
9. Relief valve setting too low.
10. Damaged vanes (see following category).
11. Vanes installed incorrectly (see "Vane Replacement").
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
- EC Rotor & Shaft required for fluid viscosities over 20,000 SSU.
3. Relief valve not opening.
4. Hydraulic hammer - pressure spikes.
5. Pump/driver
misalignment.
6. Excessively worn vanes or vane slots.
7. Settled or solidified material in the pump at start-up.
Mechanical Seal
Leakage
1. O-rings not compatible with the liquids pumped.
2. O-rings nicked, cut or twisted
3. Shaft at seal area damaged, worn or dirty.
4. Ball bearings overgreased.
5. Excessive
cavitation.
6. Mechanical seal faces cracked, scratched, pitted or dirty.
