Fault diagnosis and maintenance skills of water ring vacuum pump

Addtime: 2020-07-18 Browse times: 2092

In the maintenance process, the fault diagnosis of water ring vacuum pump is a key link. The following several common faults and solutions are proposed for targeted fault diagnosis of water ring vacuum pump. I hope you can solve the thorny problems as soon as possible.




1. No liquid supply, insufficient liquid supply or insufficient pressure:




(1) the vacuum pump is not filled with water or properly vented;




Solution: check whether the vacuum pump shell and inlet pipeline are fully filled with liquid.




(2) the speed is too low;




Solution: check whether the wiring of the motor is correct, whether the voltage is normal or whether the steam pressure of the turbine is normal.




(3) the water head of the system is too high;




Solution: check the head of the system (especially the friction loss).




(4) the suction head is too high;




Solution: check the existing net head (too small or too long inlet line will cause great friction loss).




(5) the impeller or pipeline is blocked;




Solution: check for obstructions.




(6) the rotation direction is wrong;




Solution: check the direction of rotation.




(7) air produced or leakage of inlet pipeline;




Solution: check the inlet line for cavitation and / or air leakage.




(8) the packing or sealing in the stuffing box is worn, so that the air leaks into the vacuum pump shell;




Solution: check the packing or seal and replace it as required, and check whether the lubrication is normal.




(9) insufficient suction head when pumping hot or volatile liquids;




Solution: increase the suction head and consult the manufacturer.




(10) the bottom valve is too small;




Solution: install the bottom valve with the correct size.




(11) the immersion depth of bottom valve or inlet pipe is not enough;




Solution: consult the manufacturer for the correct immersion depth. Use baffle to eliminate eddy current.




(12) impeller clearance is too large;




Solution: check the clearance.




⒀ impeller damaged;




Solution: check the impeller and replace it as required.




The impeller diameter is too small;




Solution: consult the manufacturer for the correct impeller diameter.




⒂ the position of pressure gauge is incorrect;




Solution: check if the position is correct and check the outlet nozzle or pipe.




2. The vacuum pump will stop after running for a while




(1) the suction head is too high;




Solution: check the existing net head (too small or too long inlet line will cause great friction loss).




(2) the impeller or pipeline is blocked;




Solution: check for obstructions.




(3) air produced or leakage of inlet pipeline;




Solution: check the inlet line for cavitation and / or air leakage.




(4) the packing or sealing in the stuffing box is worn, which makes air leak into the vacuum pump shell;




Solution: check the packing or seal and replace as needed. Check whether the lubrication is normal.




(5) insufficient suction head when pumping hot or volatile liquids;




Solution: increase the suction head and consult the manufacturer.




(6) the immersion depth of bottom valve or inlet pipe is not enough;




Solution: consult the manufacturer for the correct immersion depth and eliminate eddy current with baffle plate.




(7) the sealing gasket of vacuum pump shell is damaged;




Solution: check the condition of the gasket and replace it as required.




3. The power consumption of vacuum pump is too high




(1) the rotation direction is wrong




Solution: check the direction of rotation.




(2) impeller damage




Solution: check the impeller and replace it as required.




(3) the rotating parts are locked




Solution: check whether the clearance of internal wear parts is normal.




(4) shaft bending




Solution: straighten the shaft or replace it as required.




(5) the speed is too high




Solution: check the winding voltage of the motor or the steam pressure delivered to the turbine.




(6) the water head is lower than the rated value. Too much liquid pumped




Solution: consult the manufacturer. Install throttle valve and cut impeller.




(7) the liquid is heavier than expected




Solution: check the specific gravity and viscosity.




(8) the stuffing box is not filled correctly (the packing is insufficient, it is not inserted or running in correctly, and the packing is too tight)




Solution: check the packing and refill the stuffing box.




(9) incorrect bearing lubrication or bearing wear




Solution: check and replace as required.




(10) the running clearance between wear rings is incorrect




Solution: check whether the clearance is correct. Replace the wear ring of the vacuum pump housing and / or impeller as required.




(11) the pipe stress on the vacuum pump shell is too large




Solution: eliminate the stress and consult the manufacturer's representative. Check alignment after stress relief.




4. The stuffing box of vacuum pump leaks too much




(1) shaft bending




Solution: straighten the shaft or replace it as required.




(2) the coupling or vacuum pump is not aligned with the driving device




Solution: check the alignment and re align if necessary.




(3) bearing lubrication is not correct or bearing wear




Solution: check and replace as required.




5. Bearing temperature too high




(1) shaft bending




Solution: straighten the shaft or replace it as required.




(2) the coupling or vacuum pump is not aligned with the driving device




Solution: check the alignment and re align if necessary.




(3) bearing lubrication is not correct or bearing wear




Solution: check and replace as required.




(4) the pipe stress on the vacuum pump shell is too large




Solution: relieve the stress and consult the manufacturer's representative. Check alignment after stress relief.




(5) too much lubricant




Solution: remove the plug, so that excessive grease can be discharged automatically. In the case of an oil lubricated vacuum pump, drain the oil to the correct level.




6. Stuffing box overheating




(1) the packing or seal in the stuffing box is worn, so that the air leaks into the vacuum pump shell




Solution: check the packing or seal and replace as needed. Check whether the lubrication is normal.




(2) the stuffing box is not filled correctly (the packing is insufficient, it is not inserted or running in correctly, and the packing is too tight)




Solution: check the packing and refill the stuffing box.




(3) packing or mechanical seal has design problems




Solution: consult the manufacturer.




(4) mechanical seal is damaged




Solution: check and replace as required. Consult the manufacturer.




(5) the shaft sleeve is scratched




Solution: repair, re machine or replace as required.




(6) the packing is too tight or the mechanical seal is not adjusted correctly




Solution: check and adjust the packing, replace or adjust the mechanical seal according to the requirements (refer to the manual or call our factory).




7. The rotating parts are difficult to rotate or have friction




(1) shaft bending




Solution: straighten the shaft or replace it as required.




(2) the running clearance between wear rings is not correct




Solution: check whether the clearance is correct. Replace the wear ring of vacuum pump shell or impeller as required.




(3) the pipe stress on the vacuum pump shell is too large




Solution: eliminate the stress and consult the manufacturer's representative. Check alignment after stress relief.




(4) the swing of shaft or impeller ring is too large




Solution: check the rotating parts and bearings, and replace the worn or damaged parts as required.




(5) there is dirt between the impeller and the wear ring of the vacuum pump shell, and there is dirt in the wear ring of the vacuum pump shell




Solution: clean and check the wear ring and replace it as required. Isolate and eliminate the source of dirt.


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