Reciprocating Pumps Trouble Shooting Guide
- Low Volumetric Efficiency
- NPSHA Too Low
- Liquid Not Delivered
- Cavitation
- Leak at Cylinder Head or Valve Cover
- Water in Crankcase/Oil
- Oil Leakage from Crankcase
- Excessive Heat in Power End
- Pump Overloads Driver
- Stuffing Box Leakage
- Stud Failure
- Excessive Valve Noise
- Inlet or Discharge Line Vibration
- Noisy Operation
- Top Low Volumetric Efficiency (Failure To Deliver Rated Capacity And Pressure)
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- Air or vapor pocket in inlet line
- Capacity of charge pump less than capacity of power pump
- Air or vapor trapped in or above inlet manifold
- Air leak in liquid supply piping system
- Loose bolts in pump inlet manifold
- Air or gases entrained in liquid
- Foreign object holding pump inlet or discharge valve(s) open
- Incorrect drive ratio
- Loose belts
- Incorrect motor or engine speed
- Loose valve covers or cylinder head
- Worn valves and seats
- Safety relief valve partially open, or not holding pressure
- Worn liners, piston rings or plungers
- Bypass valve open, or not holding pressure
- Blown liner gasket
- NPSHA not sufficient
- Liquid bypassing internally
- Foreign object blocking liquid passage
- Vortex in supply tank
- Insufficient power delivered by motor
- Top NPSHA Too Low
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- Inlet line partially clogged
- Liquid vapor pressure too high
- Liquid pumping temperature too high
- Restricted inlet pipe fittings
- Inlet line too long
- Too many pipe fittings
- Too small inlet line
- Too low static inlet head
- Too low atmospheric pressure
- Top Liquid Not Delivered
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- Pump not primed
- Air or vapor pocket in inlet line
- Clogged inlet line
- All inlet valves propped open
- All discharge valves propped open
- Loose bolts in pump inlet manifold
- Too high valve velocities
- Top Cavitation
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- NPSHA too low
- Liquid NOT Delivered to Pump Inlet Connection
- Excessive Stuffing Box Leakage
- NPSHR too high
- Top Leak at Cylinder Head or Valve Cover
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- Over Recommended Pressure
- Loose Cylinder Head/Valve Cover
- Damaged Gasket/O-ring
- Top Water in Crankcase/Oil
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- Water Condensation
- Worn seals
- Clogged Air Breather(s)
- Worn Crankcase Packing
- Loose Covers
- Top Oil Leakage from Crankcase
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- Oil Level/Temperature Too High
- Worn seals
- Worn Crankcase Packing
- Loose Crankcase Cover
- Top Excessive Heat in Power End
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- Pump Running Backward/RPM too low 2) Insufficient Oil in Power End
- Excessive Oil in Power End
- Incorrect Oil Viscosity
- Operating Pump above Recommended Pressure 6) Main Bearings too Tight
- Drive Misaligned
- Belts too Tight
- Discharge Valve, one or more, Stuck Open 10) Insufficient Cooling
- Pump RPM too Low
- Inadequate Ventilation
- Liquid End Packing Adjusted too Tight (adjustable style packing only)
- Top Pump Overloads Driver
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- Pump RPM too High
- Low Voltage or other Electrical Trouble
- Trouble with Engine, Turbine, Gear Reducer or other Related Equipment
- Excessive Discharge Line Pressure
- Clogged Discharge Line
- Closed/Throttled Valve in Discharge Line
- Incorrect Plunger/Piston Size for Application
- Improper Bypass Conditions
- Over-tightened Stuffing Box Glands on Adjustable Packing
- Top Stuffing Box Leakage
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- Worn Packing
- Worn rods or plunger
- Worn stuffing boxes
- Wrong size packing
- Worn O-ring seal (replaceable boxes)
- Top Stud Failure
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- Excessive discharge pressure
- Improper torquing of nuts
- Shock overload caused by pump cavitation
- Top Excessive Valve Noise
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- Broken or weak valve spring
- Pump cavitation
- Air leak in inlet piping or loose bolts in pump inlet manifold
- Air trapped above inlet valve
- Top Inlet or Discharge Line Vibration
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- Piping inadequately supported
- Inlet line too long or too small in diameter
- Too many bends in inlet line
- Multiple pump installations operating in phase
- Obstruction Under Valve(s)
- Packing Worn
- Operating Above Recommended Pressure or RPM 8) Low NPSHA
- Top Noisy Operation (Be sure to differentiate between liquid knock and mechanical knock - very few knocks are mechanical on new installations.)
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- Piston or plunger loose
- Valve noise amplified through power end
- Pump cavitation
- Liquid knock
- Air leak in inlet piping
- Loose bolts in pump inlet manifold
- Hydraulic noise in liquid end
- Loose or worn crosshead pins and bushings
- Loose connecting rod cap bolt
- Worn connecting rod bearings
- Worn crosshead
- Main bearing end play excessive
- Worn gears or chains
- Gears or chains out of line
- Pump running backward
- Partial loss of prime
- Shocks in piping system
- Water in power end crankcase
- Poorly supported piping, abrupt turns in piping, piping misaligned, pipe size too small