Troubleshooting

When a failure occurs, it is essential to investigate the potential causes in accordance with the list below and to respond appropriately.
The list shows common failures and actions to be taken. Please be aware that combined factors may be behind each cause. Please give us detailed information when you contact us for troubleshooting.

• • Turbopumps
  • Fans & Blowers

• • Failure	Cause	Recovery Procedure
    Lost or reduced pump capacity	Foreign matter caught in the impeller	Disassemble and clean the unit.
    	Occurrence of cavitation	Check and review the operating water level conditions.
    	Actual head and loss of head higher than planned	Reconsider actual head and line loss.
    	Wearing ring abrasion	Replace the wearing ring.
    	Air intake through the gland	Retighten the gland packing. Replace the gland packing.
    	Incomplete filling	Perform priming again. Inspect and repair air leakage from the suction system. Inspect water system components (vacuum pump integrity, leakage from air piping, etc.) Retighten the gland packing. Inspect and clean the priming detector.
    Overloading	Excessive RPM	Adjust the power supply.
    	Flow rate too high or too low	Adjust the discharge valve opening.
    	Ingress of mud or foreign matter	Disassemble and clean the unit. Clean the suction sump and take measures to prevent foreign matter ingress.
    	Overtightened gland packing	Loosen the gland packing
    	Frozen pump	Have it thaw out.
    	Misaligned shaft	Perform alignment.
    	Damaged bearing	Replace the bearing.
    	Interference of a rotating part	Disassemble and adjust. Replace the interfering part.
    Overheating of the body	Flow rate too low	Adjust the discharge valve opening.
    	Continuous shutoff operation	Open the discharge valve.
    	Minimum flow too low	Change the minimum flow.
    	Interference of a rotating part	Disassemble and adjust. Replace the interfering part.
    Leakage from the body	Insufficient tightening of bolts	Shut down the pump and the retighten the bolts evenly.
    	Deteriorated packing	Replace the packing.
    Rise in gland temperature	Overtightened packing	Loosen the gland follower and then carefully tighten it evenly.
    	Incompletely inserted packing	Remove and insert the packing again.
    	Improperly placed lantern ring	Adjust the placement.
    	Inappropriate seal water level	Adjust with the seal water valve to achieve the required level.
    	Inappropriate seal water pressure	Adjust with the seal water valve. Review the supply pressure.
    Heating of bearings	No lube oil left	Refill the lube oil tank.
    	Excessive lubrication	Adjust the oil amount appropriately.
    	Deteriorated lube oil	Exchange lube oil.
    	Shortage of cooling water	Inspect the cooling water system components. Increase the cooling water supply rate.
    	Incorrect type of lube oil used	Replace it with the correct type.
    	Foreign matter ingress	Clean the bearing. Exchange lube oil.
    	Axial runout	Disassemble and repair.
    	Rattling or other bearing defects	Replace the bearing.
    	Damaged bearing	Replace the bearing.
    	Misaligned shaft	Perform alignment.
    Vibration noise	Bent shaft	Repair or replace the shaft
    	Shaft coupling defect	Replace the rubber rings of the shaft coupling bolts.
    	Defective alignment	Perform alignment again.
    	Damaged bearing	Replace the bearing.
    	Foreign matter caught	Remove the foreign matter.
    	Rotor interference	Disassemble and adjust. Replace the interfering part.
    	Vibrating pipe	Install a support.
    	Air suction	Raise the suction water level. Install a vortex breaker.
    	Damaged or deteriorated foundation	Repair or reconstruct the foundation.
    	Loosened bolts	Retighten them.
    	Factors related to the drive	Check for abnormalities in the drive. Repair the drive.

    Failure	Cause	Recovery Procedure
    Increased vibration	Worn impeller	Repair the worn part and adjust the balance.
    	Corroded impeller	Repair the corroded part and adjust the balance.
    	Increased dust	Clean and adjust the balance.
    	Dust adhered to the impeller	Clean and adjust the balance.
    	Imbalance	Adjust the balance.
    	Bent shaft	Replace the rotor.
    	Misalignment	Perform realignment.
    	Damaged or worn bearing	Antifriction bearing: Replace the bearing. Sleeve bearing: Replace the white metal lining or the bearing.
    	Ingress of dust into bearings	Remove dust, clean the bearings, and replace the oil.
    	Thrust bearing clearance too wide	Readjust or repair/replace the bearing.
    	Interference	Replace the component or disassemble and clean the component (if dust accumulation is observed).
    	Worn rubber bushings in JIS flange coupling	Replace them.
    	Worn gear coupling teeth	Replace them.
    	Deformed disc coupling element	Replace the element.
    	Insufficient foundation stiffness	Reinforce and repair the foundation.
    	Defective installation	Perform realignment.
    	Uneven compression of the packing seal	Perform realignment.
    	Inappropriate damper opening	Adjust actuators and attachments.
    	Surging	Adjust the opening of the damper or inlet guide vane to reach an operating point along the downward slope of the characteristic curve.
    	Foreign matter ingress from the inlet or outlet	Remove the foreign matter, disassemble, and clean.
    	Abnormally high inlet gas temperature	Measure gas temperature and take necessary action.
    	Fluid excitation	Reduce vortex formation. Reinforce or structurally modify the duct.
    	Power supply imbalance	Investigate imbalance in the power supply voltage and take necessary action.
    	Instrumentation failure	Calibrate or replace the instrumentation.
    Abnormal noise	Bent shaft	Replace the rotor.
    	Too much or too little lube oil	Refill the oil tank and adjust.
    	Damaged or worn bearing	Antifriction bearing: Replace the bearing. Sleeve bearing: Replace the white metal lining or the bearing.
    	Thrust bearing clearance too wide	Readjust or repair/replace the bearing.
    	Interference	Replace the component or disassemble and clean the component (if dust accumulation is observed).
    	Uneven compression of the packing seal	Perform realignment.
    	Inappropriate damper opening	Adjust actuators and attachments.
    	Surging	Adjust the opening of the damper or inlet guide vane to reach an operating point along the downward slope of the characteristic curve.
    	Fluid excitation	Reduce vortex formation. Reinforce or structurally modify the duct.
    Rise in bearing temperature	Too much or too little lube oil	Refill the oil tank and adjust.
    	Damaged or worn bearing	Antifriction bearing: Replace the bearing. Sleeve bearing: Replace the white metal lining or the bearing.
    	Ingress of dust into bearings	Remove dust, clean the bearings, and replace the oil.
    	Thrust bearing clearance too wide	Readjust or repair/replace the bearing.
    	Interference	Replace the component or disassemble and clean the component (if dust accumulation is observed).
    	Abnormally high inlet gas temperature	Measure gas temperature and take necessary action.
    	Instrumentation failure	Calibrate or replace the instrumentation.
    Overload at startup	Damaged or worn bearing	Antifriction bearing: Replace the bearing. Sleeve bearing: Replace the white metal lining or the bearing.
    	Interference	Replace the component or disassemble and clean the component (if dust accumulation is observed).
    	Inappropriate damper opening	Adjust actuators and attachments.
    	Low inlet gas temperature	Measure gas temperature and take necessary action.
    	Power supply imbalance	Investigate imbalance in the power supply voltage and take necessary action.
    	Instrumentation failure	Calibrate or replace the instrumentation.
    Overload during operation	Damaged or worn bearing	Antifriction bearing: Replace the bearing. Sleeve bearing: Replace the white metal lining or the bearing.
    	Interference	Replace the component or disassemble and clean the component (if dust accumulation is observed).
    	Low inlet gas temperature	Measure gas temperature and take necessary action.
    	Change in suction gas composition	Analyze gas composition and take necessary action.
    	Power supply imbalance	Investigate imbalance in the power supply voltage and take necessary action.
    	Instrumentation failure	Calibrate or replace the instrumentation.
    Fluctuation in flow rate/pressure	Worn impeller	Repair the worn part and adjust the balance.
    	Corroded impeller	Repair the corroded part and adjust the balance.
    	Inappropriate damper opening	Adjust actuators and attachments.
    	Surging	Adjust the opening of the damper or inlet guide vane to reach an operating point along the downward slope of the characteristic curve.
    	Pressure lower than the design point	Measure gas temperature, analyze gas composition, and take necessary action.
    	Foreign matter ingress from the inlet or outlet	Remove the foreign matter, disassemble, and clean.
    	Power supply imbalance	Investigate imbalance in the power supply voltage and take necessary action.
    	Instrumentation failure	Calibrate or replace the instrumentation.
    Load fluctuation	Increased dust	Clean and adjust the balance.
    	Interference	Replace the component or disassemble and clean the component (if dust accumulation is observed).
    	Inappropriate damper opening	Adjust actuators and attachments.
    	Surging	Adjust the opening of the damper or inlet guide vane to reach an operating point along the downward slope of the characteristic curve.
    	Foreign matter ingress from the inlet or outlet	Remove the foreign matter, disassemble, and clean.
    	Change in suction gas composition	Analyze gas composition and take necessary action.
    	Power supply imbalance	Investigate imbalance in the power supply voltage and take necessary action.
    	Instrumentation failure	Calibrate or replace the instrumentation.
    Worn impeller	Increased dust	Clean and adjust the balance.
    Corroded impeller	Clogged drain pipe	Clean the pipe.
    	Change in suction gas composition	Analyze gas composition and take necessary action.
    Bent shaft	Damaged or worn bearing	Antifriction bearing: Replace the bearing. Sleeve bearing: Replace the white metal lining or the bearing.
    	Interference	Replace the component or disassemble and clean the component (if dust accumulation is observed).
    	Uneven compression of the packing seal	Perform realignment.
    	Abnormally high inlet gas temperature	Measure gas temperature and take necessary action.
    Casing corrosion	Clogged drain pipe	Clean the pipe.
    	Change in suction gas composition	Analyze gas composition and take necessary action.