The faults in the operation of industrial pump can be divided into corrosion and wear, mechanical fault, performance fault and shaft seal fault. These four kinds of fault camphor often affect each other and are difficult to separate. For example, the corrosion and wear of impeller will cause performance failure and mechanical failure, and the damage of shaft seal will also cause performance failure and mechanical failure.
1. Corrosion and wear
The main reason of corrosion is improper selection of materials. When corrosion failure occurs, it should be solved from two aspects of medium and material.
Wear often occurs in the transportation of slurry, the main reason is that there are solid particles in the medium. For the pump conveying slurry, in addition to the wear-resistant parts of the pump, the shaft seal shall be washed with clean liquid to avoid the invasion of impurities, and the flushing facilities shall be adopted in the pump to avoid the blockage of the flow channel. In addition, the wearing parts should be replaced when the wear amount is fixed.
2. Mechanical failure
Vibration and noise are the main mechanical faults. The main causes of vibration are bearing damage, cavitation and poor assembly, such as different shafts of pump and prime mover, insufficient foundation stiffness or foundation sinking, poor piping strength, etc.
3. Performance failure
Performance failure mainly refers to the flow, head shortage, pump cavitation and drive machine overload and other accidents.
Shaft seal failure mainly refers to leakage at the seal. The main reasons for leakage of packing seal are improper selection of packing and wear of shaft sleeve.
The main reason of mechanical seal leakage is the damage of the end face or the scratch or wrinkle of the auxiliary seal ring.
1.Reason
(1) Too much lubricating oil
(2) Too little lubricating oil
(3) Deterioration of lubricating oil
(4) The unit is not concentric
(5) Vibration
2.Method
(1) Oil reduction
(2) Come on
(3) Drain and clean the oil tank and add new oil
(4) Check and adjust the alignment of the pump and prime mover
(5) Check the balance of the rotor or operate at a small flow rate
1.Reason
(1) Air in suction line or pump
(2) Inlet or outlet side pipe valve closed
(3) Use head higher than the maximum head of the pump
(4) Air leakage in pump suction pipe
(5) Wrong impeller rotation direction
(6) Suction height too high
(7) Suction line too small or debris blocked
(8) Speed discrepancy
2.Method
(1) Fill with liquid and remove air
(2) Open the valve
(3) Replace the pump with high lift
(4) Prevent leakage at the inlet side
(5) Correct motor steering
(6) Reduce the installation height of the pump and increase the pressure at the inlet
(7) Increase suction pipe diameter and eliminate blockage
(8) Make the motor speed meet the requirements
1.Reason
(1) Impeller damaged
(2) Excessive wear of sealing ring
(3) Insufficient revolutions
(4) Inlet or outlet valve not fully open
(5) Air leakage in suction line
(6) There is a blockage in the pipe
(7) The density of the medium does not meet the requirements of the pump
(8) The head of the device is inconsistent with that of the pump
2.Method
(1) Replace the impeller with a new one
(2) Replace seal
(3) Increase speed as required
(4) Fully open
(5) Seal up the leak
(6) Remove blockage
(7) Recalculate or replace the motor with proper power
(8) Try to reduce the installation height of the pump
1.Reason
(1) Improper selection of sealing element materials
(2) Serious wear of friction pair
(3) The dynamic and static rings are not even
(4) Too large friction pair, static ring broken
(5) O-ring damaged
2.Method
(1) Explain the medium condition to the pump supplier with appropriate seals
(2) Replace worn parts and adjust spring pressure
(3) Readjust the seal assembly
(4) Dismantle and replace the static ring of the whole pump so that the Perpendicularity Error with the shaft is less than 0.10, and install the seal assembly as required
(5) Replace O-ring
1.Reason
(1) The center line of pump shaft and motor shaft is out of alignment
(2) Shaft bending
(3) Bearing wear
(4) Pump cavitation
(5) The rotating part and the fixed part are worn
(6) Rotating part out of balance
(7) The pipeline or pump is blocked by sundries
(8) Closed the inlet valve
2.Method
(1) Correct alignment
(2) Replace the shaft with a new one
(3) Replace bearing
(4) Consult factory
(5) Overhaul the pump or improve the service condition
(6) Check the cause and try to eliminate it
(7) Check the blowdown
(8) Open the inlet valve and adjust the outlet valve
1.Reason
(1) Pump and prime mover are not in alignment
(2) Increase of relative density of medium
(3) Friction in rotating part
(4) The resistance of the device becomes low, so that the running point is inclined to the place with large flow
2.Method
(1) Adjust the alignment of pump and prime mover
(2) Change operation process
(3) Repair friction parts
(4) Check and adjust the pressure of suction and discharge pipeline to the original change
