High Temperature Resistant Centrifugal Pump Installer
Here are 10 common faults of fluoroplastic centrifugal pumps and their possible causes and solutions

2023/07/31

1.Shaft seal overheating Causes and solutions: 

(1) Packing is too tight or friction occurs. Solution: Loosen the packing and check the water seal pipe. 

(2) Water seal ring and water seal pipe misaligned. Solution: Realign them. 

(3) Poor flushing and cooling. Solution: Check the flushing and cooling circulation pipe. 

(4) Mechanical seal failure. Solution: Check every sealing component of the mechanical seal.

2.Excessive rotor oscillation in the fluoroplastic centrifugal pump Causes and solutions: 

(1) Improper use, operating conditions deviate from the pump's design conditions. Solution: Strictly follow the technical specifications to operate the pump within the design conditions. 

(2) Insufficient balance. Solution: Clean the balance pipeline. 

(3) Material of the balance disc and its base does not meet the requirements. Solution: Replace with materials that meet the requirements.

3.Inability to start or high starting load of the fluoroplastic centrifugal pump Causes and solutions:

(1) Abnormal motor or power supply. Solution: Check the power supply and motor condition. 

(2) Pump jammed. Solution: Manually turn the coupling to check and, if necessary, dismantle and inspect for common faults in the dynamic and static parts. 

(3) Packing is too tight. Solution: Loosen the packing. 

(4) Discharge valve not closed. Solution: Close the discharge valve and restart. 

(5) Obstruction in the balance pipe. Solution: Clean the balance pipe.

fluoroplastic centrifugal pump

4.Pump does not discharge liquid Causes and solutions: 

(1) Insufficient priming (or gas inside the pump not fully discharged). Solution: Prime the pump again. 

(2) Incorrect pump rotation direction. Solution: Check the rotation direction. 

(3) Pump speed too low. Solution: Check the speed and increase it if necessary. 

(4) Strainer clogged, check valve malfunction. Solution: Check the strainer and clear any debris. 

(5) Suction head too high or suction tank experiencing a vacuum. Solution: Reduce the suction head or check the pressure in the suction tank.

5.Interruption in fluid discharge after starting in the fluoroplastic centrifugal pump Causes and solutions: 

(1) Air leakage in the suction pipeline. Solution: Check the connection of the suction side pipeline and the sealing condition of the stuffing box. 

(2) Gas in the suction side not fully discharged during priming. Solution: Prime the pump again.

 (3) Sudden blockage in the suction side. Solution: Stop the pump and remove the blockage. 

(4) Large amount of gas in the suction. Solution: Check for vortex at the suction inlet and whether the immersion depth is too shallow.

6.Insufficient flow in the fluoroplastic centrifugal pump Causes and solutions:

(1) Increase in static head of the system. Solution: Check the liquid height and system pressure.

(2) Increase in resistance loss. Solution: Check the pipeline and check valve for obstructions.

(3) Excessive wear of the casing and impeller wear ring. Solution: Replace or repair the wear ring and impeller.

(4) Leakage from other parts. Solution: Check the shaft seal and other parts. 

(5) Clogging, wear, or corrosion of the pump impeller. Solution: Clean, inspect, and replace as needed.

7.Insufficient head in the fluoroplastic centrifugal pump Causes and solutions:

(1) Impeller installed in reverse (double suction impeller). Solution: Check the impeller.

 (2) Liquid density and viscosity do not match the design standard. Solution: Check the physical properties of the liquid. 

(3) Operating flow rate too high. Solution: Reduce the flow rate.

8.High power consumption during operation of the fluoroplastic centrifugal pump Causes and solutions: 

(1) Friction between impeller and wear ring, impeller and casing. Solution: Inspect and repair. 

(2) Excessive flow rate. Solution: Reduce the flow rate.

 (3) Increase in liquid density. Solution: Check the liquid density. 

(4) Packing is too tight or dry friction occurs. Solution: Loosen the packing and check the water seal pipe.

 (5) Bearing damage. Solution: Inspect and repair or replace the bearings. 

(6) Excessive speed. Solution: Check the driving machine and power supply.

 (7) Pump shaft misalignment. Solution: Correct the pump shaft

(8) Error in the axial force balancing device. Solution: Check the balancing holes and whether the return pipe is blocked. 

(9) Coupling misalignment or excessive axial clearance. Solution: Check the alignment and adjust the axial clearance.

9.Vibration or abnormal noise in the fluoroplastic centrifugal pump Causes and solutions: 

(1) Vibration frequency is 0~40% of the working speed. Causes include excessive bearing clearance, loose axle sleeves, impurities in the oil, abnormal oil quality (viscosity, temperature), foaming of oil due to gas or process fluid, and bearing damage. Solution: Check and take effective measures such as adjusting bearing clearance, removing impurities from the oil, and replacing it with fresh oil. 

(2) Vibration frequency is 60%~100% of the working speed. Causes include excessive sealing clearance, loose retaining rings, and damaged seals. Solution: Inspect, adjust, or replace the seals.

 (3) Vibration frequency is 2 times the working speed. Causes include misalignment, loose coupling, friction in the sealing device, deformation of the casing, bearing damage, resonant support, and damaged thrust bearings. Solution: Inspect and take effective measures such as repairs, adjustments, or replacements.

 (4) Vibration frequency is n times the working speed. Causes include pressure pulsation, misalignment, casing deformation, friction in the sealing, resonant support or foundation, pipeline-machine resonance. Solution: Strengthen the foundation or pipeline.

 (5) Very high vibration frequency. Causes include shaft friction, imprecise sealing, loose bearings, abnormal shrink fit, etc. Solution: Strengthen the foundation or pipeline.

10.Bearing overheating in the fluoroplastic centrifugal pump Causes and solutions: 

(1) The bearing pad scraping does not meet the requirements. Solution: Re-repair the bearing pad or replace it. 

(2) The bearing clearance is too small. Solution: Readjust the bearing clearance or scrape it. 

(3) Insufficient lubricating oil or poor oil quality. Solution: Increase the oil quantity or replace the lubricating oil. 

(4) Poor installation of bearings. Solution: Check the bearing installation according to the requirements and rectify any deviations.

 (5) Cooling water circuit interrupted. Solution: Inspect and repair it. 

(6) Bearing damage or looseness. Solution: Repair or replace the bearing. If loose, tighten the relevant bolts. 

(7) Pump shaft deformation. Solution: Correct the pump shaft. 

(8) Deformation of the slinger ring, the slinger ring cannot rotate, and failure to deliver oil

   

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