Boiler feed water pump - Troubleshooting !!!

Symptom	Possible cause of trouble and remedies   (each number is defined in the list below)
Pump does not deliver water.	1,2,3,4,6,11,14,16,17,22,23
Insufficient capacity delivered.	2,3,4,5,6,7,9,10,11,14,17,20,22,23,30,31
Insufficient pressure developed.	5,14,16,17,20,22,30,31
Pump loses prime after starting.	2,3,5,6,7,11,12
Pump requires excessive power.	15,16,17,18,19,20,23,26,27
Pump vibrates or it is noisy.	2,3,4,9,10,11,21, 23,25,26,27,28,30,41,45,46,47
Bearings have short life.	26,27,28,41,46,47
Pump overheats and seizes.	1,4,21,22,,27,28,41
Suction troubles	Remedies
1.   Pump not primed.	Ensure that casing fully filled and water comes                                                  out from air cock.
2.   Pump or suction pipe not completely filled with liquid.	Check leaking foot valve in case of negative suction.
3.   Suction lift too high.	Reduce by lowering pump elevation or increase water level.
4.   Insufficient margin between pressure and vapour pressure.	Check that NPSH available is at least 1 meter suction more than NPSH required.
5.   Excessive amount of air or in liquid.	Check the reasons and eliminate. Gas entrapped gas in liquid. Air may be passing through suction joints.
6.   Air pocket in suction line.	Ensure pipe fully filled, no concentric bend for  Negative suction.
7.   Air leaks into suction line.	Tighten pipe joints with solution.
8.
9.   Foot valve too small or leaking.	Replace / Attend.
10.Foot valve partially clogged.	Clean.
11.Inlet of suction pipe not sufficiently submerged.	Ensure adequate submergence that foot valve is not exposed.
12.Water seal pipe clogged.	Clean or change.
14. Speed too low.	Check motor RPM, supply frequency Motor nameplate, speed should be as specified on pump nameplate.
15. Speed too high.	Check motor RPM, supply frequency.
16. Direction of rotating wrong.	Check correct direction of rotation for motor before coupling to motor.
17.Total head of system higher than design head of pump.	Check the causes and refer to Manual & Product data sheet . Measure with pressure gauge.
18.Total head of system lower than pump design head.	Check the causes and refer to Manual & Product data sheet. Measure with pressure gauge.
19.Specific gravity of liquid different from design.	Refer to Manual & Product data sheet
20. Viscosity of liquid different           from design.	Refer to Manual & Product data sheet
21. Operation at very low capacity.	Check the causes and refer to M&P, Operate pump at rated duty.
22. Parallel operation of pumps unsuitable for such operation.	Refer to Manual & Product data sheet with characteristics curves of pump.
Mechanical troubles	Remedies
23. Foreign matter in impeller.	Open and clean.
25.Foundations not rigid	Check vibration on Base frame, check hollowness
26.Shaft bent	Dismantle and check, Replace shaft
27.Rotating part rubbing on                stationary part	Incorrect assembly, correct assembly
28.Bearing worn	Shaft run out, replace if required
30.Impeller damaged	Replace
31.Casing gasket defective, permitting internal leakage	Replace
32.Shaft or shaft  bushes worn or scored at packing	Replace
41. Excessive thrust caused by  mechanical failure inside pump or by failure of hydraulic balancing   device.	Check pump operation and assembly
45.Dirt in bearings	Investigate the cause and clean bearing
46.Rusting of bearings from water in housing	Arrest water ingress
47.Excessive cooling of water-       cooled bearing, resulting in condensation of atmospheric moisture in bearing housing	Reduce cooling water flow