Support

Maintenance and inspection

DMW provides support for the maintenance and inspection of not only the pump itself but also the entire pump facility, including the electrical equipment.
In order to keep pump facilities in good condition for a long period of time and reduce maintenance costs, it is important to conduct regular inspections and perform maintenance based on the inspection results.

We have a catalogue regarding maintenance and inspection, so if you need one, please contact us and request it.

Inquiry

Deterioration diagnosis through vibration analysis
Visual inspection of the inside of the pump using an industrial endoscope

technical assistance

If you have a pump facility for which you would like to develop a maintenance plan, please feel free to contact us. Our engineers will provide full support regarding the necessity and content of maintenance.

Blowers
Pumps

Troubleshooting

When a breakdown occurs, it is necessary to investigate the possible causes and take appropriate measures. We introduce common causes of breakdowns and their countermeasures.
The cause may be a combination of various factors, so please consult with our technicians for more details.

Turbo pump

Failure details	cause	Recovery Method
Unable to pump or reduced pumping volume	Foreign matter is stuck in the impeller	Disassemble and clean
	Cavitation is occurring	Check and review water level conditions during operation
	Actual head and head loss are higher than planned	Re-examination of actual head and pipeline loss
	Liner ring wear	Replacing the liner ring
	It draws air from the ground.	Tighten the gland packing. Replacement of gland packing
	Incomplete filling	Priming the tank again Check and repair air leaks in the intake system Inspection of water system equipment (vacuum pump integrity, air piping leaks, etc.) Retightening of gland packing Checking and cleaning the full water detector
overload	Excessive rotation speed	Adjusting the power supply
	Excessive or insufficient water volume	Adjust the discharge valve opening
	Mud and foreign matter contamination	Disassemble and clean Clean the suction tank and take measures to prevent foreign objects from entering.
	Gland packing is overtightened	Loosen the gland packing
	Pump freeze	Unzip
	Misalignment of shaft core	Centering
	Bearing Damage	Bearing replacement
	Rotating Contact	Disassemble and fix Replacement of contact parts
Overheating of the device	Insufficient amount of water	Adjust the discharge valve opening
	Continuous shutoff operation	Open the discharge valve
	Minimum flow is too low	Change in minimum flow
	Rotating Contact	Disassemble and fix Replacement of contact parts
Body leakage	Bolts not tightened properly	Stop the pump and then tighten the bolts evenly.
Body leakage	Deterioration of packing	Replacing the packing
Ground temperature rise	Packing overtightened	Loosen the packing gland once and tighten it carefully and evenly.
	Improper insertion of packing	Reinsert the packing
	Lantern ring not positioned properly	Adjust the position
	The amount of water sealing is not appropriate	Adjust the water seal valve to the specified amount.
	Sealing pressure is not appropriate	Adjust with the seal valve Review of supply pressure
Heat generation in bearings	Out of lubricant	Supplying lubricating oil
	Excessive amount of lubricating oil	Use the right amount of lubricant
	Deterioration of lubricating oil	Lubricating Oil Change
	Cooling water shortage	Inspection of cooling water system equipment Increase the amount of cooling water supplied
	The type of lubricant is not appropriate.	Exchange it for a genuine one
	Foreign matter contamination	Cleaning Lubricating Oil Change
	Shaft runout	Disassembly and repair
	Bearing defects such as backlash	Bearing replacement
	Bearing Damage	Bearing replacement
	Misalignment of shaft core	Centering
Vibration and noise	The main shaft is bent	Modify or replace the spindle
	Defective shaft coupling	Rubber ring replacement for shaft coupling bolt
	Improper alignment	Re-center the
	Bearing Damage	Bearing replacement
	Foreign object is stuck	Remove the object
	Rotating bodies are in contact	Disassemble and fix Replacement of contact parts
	The pipe is vibrating	Support installation
	Breathing air	Raise the suction water level Installation of vortex prevention device
	Damage and deterioration of foundations	Repair or rebuild foundations
	Loose bolts	Tighten further
	Influence of the driving machine	Check if there is anything wrong with the drive unit Repair the drive unit

Van Blois

Failure details	cause	Recovery Method
Increased vibration	Impeller wear	Repairing worn parts and adjusting balance
	Impeller corrosion	Repair of corroded parts and balance adjustment
	Increased dust volume	Cleaning and balancing
	Dust adhesion to the impeller	Cleaning and balancing
	Unbalance	Balance Changes
	Shaft bending	Replacing the Rotating Body
	Misalignment	readjustment
	Bearing damage and wear	Rolling bearings: Bearing replacement Plain bearing: Reupholstering with white metal or replacing the bearing
	Dust getting into bearings	Remove dust, clean, and replace with new oil
	Thrust bearing large clearance	Readjustment, bearing repair and replacement
	contact	Parts replacement, disassembly and cleaning (in case of dust accumulation)
	Wear of JIS flange type coupling rubber bush	exchange
	Wear of gear coupling teeth	exchange
	Deformation of disk-type coupling elements	Element replacement
	Insufficient foundation rigidity	Foundation reinforcement and repair
	Improper installation	readjustment
	Packing seal is not evenly contacted	readjustment
	Dampers not opening properly	Adjustment of the control unit and connection mechanism
	Surging	By adjusting the damper or suction vane opening, operation occurs in the downward sloping part of the characteristic curve.
	Foreign matter entering through suction and discharge	Removal of foreign objects, disassembly and cleaning
	Abnormally high inlet gas temperature	Gas temperature measurement and treatment
	fluid excitation	Reduced vortex generation Duct reinforcement and structural modification
	Power imbalance	Power supply voltage imbalance investigation and correction
abnormal sound	Shaft bending	Replacing the Rotating Body
	Excess or shortage of lubricant	Supply and adjust the appropriate amount
	Bearing damage and wear	Rolling bearings: Bearing replacement Plain bearing: Reupholstering with white metal or replacing the bearing
	Thrust bearing large clearance	Readjustment, bearing repair and replacement
	contact	Parts replacement, disassembly and cleaning (in case of dust accumulation)
	Packing seal is not evenly contacted	readjustment
	Dampers not opening properly	Adjustment of the control unit and connection mechanism
	Surging	By adjusting the damper or suction vane opening, operation occurs in the downward sloping part of the characteristic curve.
	fluid excitation	Reduced vortex generation Duct reinforcement and structural modification
Bearing temperature rise	Excess or shortage of lubricant	Supply and adjust the appropriate amount
	Bearing damage and wear	Rolling bearings: Bearing replacement Plain bearing: Reupholstering with white metal or replacing the bearing
	Dust getting into bearings	Remove dust, clean, and replace with new oil
	Thrust bearing large clearance	Readjustment, bearing repair and replacement
	contact	Parts replacement, disassembly and cleaning (in case of dust accumulation)
	Abnormally high inlet gas temperature	Gas temperature measurement and treatment
	Instrumentation failure	Calibration and replacement of instruments
Starting Overload	Bearing damage and wear	Rolling bearings: Bearing replacement Plain bearing: Reupholstering with white metal or replacing the bearing
	contact	Parts replacement, disassembly and cleaning (in case of dust accumulation)
	Dampers not opening properly	Adjustment of the control unit and connection mechanism
	Inlet gas temperature drop	Gas temperature measurement and treatment
	Power imbalance	Power supply voltage imbalance investigation and correction
	Instrumentation failure	Calibration and replacement of instruments
Overload during operation	Bearing damage and wear	Rolling bearings: Bearing replacement Plain bearing: Re-cover with white metal or replace bearing.
	contact	Parts replacement, disassembly and cleaning (in case of dust accumulation)
	Inlet gas temperature drop	Gas temperature measurement and treatment
	Changes in intake gas composition	Gas component analysis and treatment
	Power imbalance	Power supply voltage imbalance investigation and correction
	Instrumentation failure	Calibration and replacement of instruments
Fluctuations in flow rate and pressure	Impeller wear	Repairing worn parts and adjusting balance
	Impeller corrosion	Repair of corroded parts and balance adjustment
	Dampers not opening properly	Adjustment of the control unit and connection mechanism
	Surging	By adjusting the damper or suction vane opening, operation occurs in the downward sloping part of the characteristic curve.
	Pressure is below specification point	Gas temperature measurement, gas composition analysis and treatment
	Foreign matter entering through suction and discharge	Removal of foreign objects, disassembly and cleaning
	Power imbalance	Investigate and correct power supply voltage imbalance
	Instrumentation failure	Calibration and replacement of instruments
Load Fluctuation	Increased dust volume	Cleaning and balancing
	contact	Parts replacement, disassembly and cleaning (in case of dust accumulation)
	Dampers not opening properly	Adjustment of the control unit and connection mechanism
	Surging	By adjusting the damper or suction vane opening, operation occurs in the downward sloping part of the characteristic curve.
	Foreign matter entering through suction and discharge	Removal of foreign objects, disassembly and cleaning
	Changes in intake gas composition	Gas component analysis and treatment
	Power imbalance	Investigate and correct power supply voltage imbalance
	Instrumentation failure	Calibration and replacement of instruments
Impeller wear	Increased dust volume	Cleaning and balancing
Impeller corrosion	Drain piping clogged	cleaning
Impeller corrosion	Changes in intake gas composition	Gas component analysis and treatment
Shaft bending	Bearing damage and wear	Rolling bearings: Bearing replacement Plain bearing: Reupholstering with white metal or replacing the bearing
	contact	Parts replacement, disassembly and cleaning (in case of dust accumulation)
	Packing seal is not evenly contacted	readjustment
	Abnormally high inlet gas temperature	Gas temperature measurement and treatment
Casing corrosion	Drain piping clogged	cleaning
Casing corrosion	Changes in intake gas composition	Gas component analysis and treatment