Common Faults and Repairs of Diaphragm Pumps
Mar,10,2025
CONTENT [HIDE]
Common fault repair
1.Causes and Treatment Methods of Insufficient or Increased Pressure of Diaphragm Pump
(1) Improper adjustment of the diaphragm pump pressure regulating valve; adjust the pressure valve to the required pressure.
(2) Failure of the pressure regulating valve; repair the pressure regulating valve.
(3) Failure of the pressure gauge; repair or replace the pressure gauge.
2. Causes and Treatment Methods of Diaphragm Pump Pressure Drop Failure
(1) Insufficient oil supply from the oil supply valve; repair the oil valve.
(2) Insufficient feed or leakage from the feed valve; inspect the feed situation and the feed valve.
(3) Oil leakage from the plunger seal; inspect the sealing part.
(4) The oil level in the oil storage tank is too low; add new oil.
(5) The pump body leaks or the diaphragm is damaged; check and replace the seal or diaphragm.
3. Causes and Treatment Methods of Insufficient Flow of Diaphragm Pump
Leakage of feed and discharge valves; Repair or replace feed valve. Damaged diaphragm, replace diaphragm. Speed is too slow, regulation fails; Repair control device, adjust speed.
4.Causes and Treatment Methods of Oil Leakage of Diaphragm Pump
Damaged or too loose gasket and seal ring; adjust or replace gasket and seal ring.
5. Pneumatic Diaphragm Pump Works, but the Flow is Small or No Liquid Flows Out
(1) Check the cavitation phenomenon of pneumatic diaphragm pump, reduce the speed of pump to allow liquid to enter the liquid chamber.
(2) Check whether the valve ball is stuck. If the operating liquid is incompatible with the elastomer of the pump, the elastomer will expand. Please replace the elastomer with appropriate material.
(3) Check whether the joint at the pump inlet is completely locked and leak-proof, especially the clamp near the valve ball at the inlet end needs to be locked.
6. The Air Valve of the Pneumatic Diaphragm Pump is Frozen
Check whether the water content of the compressed air is too high and install air drying equipment.
7.Bubbles are Generated at the Outlet of the Pneumatic Diaphragm Pump
Check whether the diaphragm is broken and whether the clamps are locked, especially the inlet pipe clamps.
8.The Liquid Flows Out from the Air Discharge Port
Check whether the diaphragm is broken and whether the diaphragm and the inner and outer clamps are clamped on the shaft.
9. The Valve Makes a Rattling Sound
Increase the Outlet or Inlet Head.
10. Guide to Disassembly and Reassembly of Pneumatic Diaphragm Pumps
Warning: Before repairing the pump, the air source piping must be removed from the pump and the air pressure in the pump must be discharged. Remove all pipes connecting the pump's inlet and outlet, and then discharge the fluid in the pump into an appropriate container. Wear protective caps, glasses, and gloves.
11. The Diaphragm Pump Does not Move or Operates Very Slowly
(1) Check the filter screen or air filter device at the air inlet for impurities.
(2) Check whether the air valve is stuck and clean the air valve with cleaning fluid.
(3) Check the air valve for wear and replace with new parts if necessary.
(4) Check the condition of the sealing parts of the center body. If they are severely worn, the sealing effect cannot be achieved and the air will be discharged from the air outlet. Due to its special structure, please only use GLYD rings.
(5) Check whether the piston in the air valve moves normally.
(6) Check the type of lubricant. If the viscosity of the added lubricant is higher than the recommended oil, the piston may get stuck or malfunction.
PS: It is Recommended to Use Light and Antifreeze Lubricating Oil.
1) The pneumatic diaphragm pump is powered by compressed air. Proper lubrication can make the pump run more stably and extend the service life of the pump.
2) Ensure the cleanliness of the compressed air. Unclean gas can easily wear the air valve. It is recommended to install a pneumatic triplex!
3) The machine should be opened and closed slowly to reduce the impact on the pipeline and diaphragm. Check whether the pipeline connection is loose before starting.
4) When transfer hazardous liquids, please connect the exhaust of the pump to a safe place to avoid danger when the diaphragm is damaged.
5) Please clean it in time after transporting liquids that are easy to dry, so as to avoid damage to the diaphragm or failure to start the next time.
6) When the pipeline is long, fix the pipeline well and do not use the pump to bear the weight and vibration of the pipeline.
Troubleshooting
1. The Pneumatic Diaphragm Pump is Running But the Flow rate is too low
(1) Check whether the pump body has cavitation spots and adjust the inlet pressure of the compressed air. Reduce the running speed of the pump body to adjust the liquid with high viscosity and concentration.
(2) Check whether the valve ball is stuck. If the delivered liquid does not match the material of the valve ball. The valve ball will swell. Please replace the valve ball and valve seat with suitable materials.
(3) Please check whether the inlet pipe is blocked.
2. The Pneumatic Diaphragm Pump Cannot Start or Moves Slowly
(1) Check whether the filter, pressure regulating and lubrication device and the air inlet filter are blocked.
(2) Check whether the air valve is stuck by impurities. Please remove the air valve and clean it, and check whether the piston in the air valve has any scratches. If the surface of the piston is bright and not pure black, it means that it has been worn and the piston and "O" ring need to be replaced. Please replace with new ones.
(3) Check whether the main shaft and "O" ring have any scratches, wear and flattening marks. If damaged, please replace them.
3. Liquid Leaks from the Air Chamber Outlet
(1) Check if the diaphragm is broken.
(2) Check if the diaphragm is properly installed and locked.
4. The outlet liquid contains a large number of bubbles
(1) Check if the diaphragm is broken.
(2) Check if the pump body and pipeline are leaking.
5. Daily Maintenance
(1) Check the operation of the diaphragm pump regularly and listen for any abnormal sounds.
(2) Check the tightness of each joint regularly.
(3) Check the lubricating oil level regularly and add it in time.
(4) Clean the debris around the pump body regularly.
(5) Replace wearing parts regularly according to the use environment and the corrosiveness of the medium.
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