Goulds Pumps AF (Axial Flow) (6"-36) MXR Bearings" - Manual (Page 45)

AF (6-36) IOM 43
5
Pump Troubleshooting (Cont’d)
PROBLEM PROBABLE CAUSE REMEDY
Lubricant level Be sure the oil level is at center line of sight glass
Improper lubricant Check lubricant for suitability
Not lubricated enough Increase frequency of grease lubrication
Broken or bent impeller vanes Check impeller dimensions and vane layout
Excessive shaft misalignment Check shaft run-out and consult factory
Inadequate lubricant cooling Check pumpage temperature and add oil cooling system if necessary
Axial thrust or radial load higher than bearing rating Calculate bearing life for make and model bearing
Bearings run hot and or fail on
a regular basis
Improper coupling lubrication
Check coupling lubrication schedule in manufacturers installation,
operation, maintenance manual
Coupling out of balance
Check pump and drive component vibration levels, rebalance coupling if
necessary
Suction pressure too high Check liquid levels and static suction pressure
Bearing incorrectly installed Check bearing orientation to sectional drawing
Impeller out of balance Check pump vibrations, if necessary rebalance impeller
Excessive shaft deflection Check shaft diameter, sag and deflection, consult factory
Pump run off design point Fill system piping completely so the impeller is submerged
Lubricant contamination Inspect oil or grease for contaminants
Piping not properly anchored Check to see if excessive pipe strain is being transferred to pump flanges
Pump and/or driver not secured to sub-base Check fasteners, if loose check alignment and re-tighten
Specific gravity higher than specified Analyze pumpage and compare to specified gravity
Viscosity higher than specified Analyze pumpage and compare to specified viscosity
Pump assembled incorrectly Compare pump assembly to instruction manual
Partly clogged impeller causing
Imbalance
Back flush pump or manually clean impeller
Broken or bent impeller or shaft Replace as required
Pump foundation not rigid or sub-base not completely secured Tighten hold down bolts on sub-base Check foundation rigidity
Impeller out of balance Check impeller balance
Motor not secure Check motor fasteners
Improper coupling lubrication
Check coupling lubrication schedule in manufacturers installation,
operation, maintenance manual
Bearing incorrectly installed Check bearing orientation to sectional drawing
Coupling out of balance
Check pump and drive component vibration levels, rebalance coupling if
necessary
Pump operating speed too close to system’s natural frequency Change speed to be +/- 20% of the pumps natural frequency
Pump is noisy or vibrates at
higher than normal levels
Impeller partly clogged Back flush pump or manually clean impeller
Impeller clearances too tight Check impeller clearances adjust if necessary
Pump assembled incorrectly Compare pump assembly to instruction manual
Pump run off design point Check head and flow, AF’s should be run at <75% BEP > 115%
Excessive shaft deflection Check shaft diameter, sag and deflection, consult factory
Worn bearings Replace
Suction or discharge piping not anchored or properly supported Anchor per Hydraulic Institute Standards manual recommendation
Suction and/or discharge valve closed or clogged Open valves to remove partially blocked condition
Excessive shaft misalignment Check shaft run-out and consult factory
Pump assembled incorrectly Compare pump assembly to instruction manual
Pump is cavitating, insufficient NPSH available System problem, increase liquid level or lower pump
Insufficient NPSH available Increase liquid level or lower pump
Excessive shaft misalignment Check shaft run-out and consult factory
Suction pressure too high Check liquid levels and static suction pressure
Bearing installed incorrectly Check bearing orientation to sectional drawing
Impeller out of balance Check pump vibrations, if necessary rebalance impeller
Overheating of seal faces Check flush flow with mfgr’s recommendation, increase if necessary
Excessive shaft deflection Check shaft diameter, sag and deflection, consult factory
Lack of seal flush to seal faces Check shaft diameter, sag and deflection, consult factory
High rate of mechanical seal
failure
Incorrect seal installation Check seal materials vs. pumpage to determine compatibility
Pump is run dry Fill system piping completely so the impeller is submerged
Pump run off design point Fill system piping completely so the impeller is submerged
Shaft/shaft sleeve worn Replace shaft or shaft sleeve if necessary
Coupling out of balance
Check pump and drive component vibration levels, rebalance coupling if
necessary
Sub-base not installed correctly Compare pump sub-base installation to instruction manual
Bearing failing Replace if necessary
Piping not properly anchored Check to see if excessive pipe strain is being transferred to pump flanges
Pump and/or driver not secured to sub-base Check fasteners, if loose check alignment and re-tighten
Specific gravity higher than specified Analyze pumpage and compare to specified gravity
Viscosity higher than specified Analyze pumpage and compare to specified viscosity
Pump assembled incorrectly Compare pump assembly to instruction manual
Head higher than rating. Reduced flow Check for fouling in the piping or obstruction in discharge
Liquid heavier than expected Check specific gravity and viscosity
Motor requires excessive
power
Incorrect rotation Jog motor and check rotation
Pump run off design point Check measured head and flow to specified head and flow
Stuffing box packing too tight Readjust packing. Replace if worn
Rotating parts binding, internal clearances too tight Check internal wearing parts for proper clearances
Table 4 (Cont’d)