Common faults and solutions of Wilton pneumatic diaphragm pumps

Common fault 1: The pump can run but the flow rate is small or no flow

1. Check whether there are air pockets in the pump; reduce the running speed of the pump to allow materials with higher concentration to flow into the liquid chamber.

2. Confirm that the vacuum required to lift the fluid does not exceed the vapor pressure of the conveyed material (to prevent cavitation).

3. Check whether the ball check valve is stuck. Swelling may occur if the material being conveyed is incompatible with the elastomer components of the pump. Replace ball check valve and seal with new suitable elastomeric material assemblies. Also, when inspecting a ball valve for wear, it is common to find that the ball valve is smaller and begins to stick to its seat. In this case, replace the ball valve and valve seat.

4. Ensure that all suction connections are airtight.

Common fault 2: Pump air valve frozen

1. If the compressed gas contains too much moisture. A dryer or hot gas generator suitable for compressed gas should be installed. Or install coalescing filters to remove moisture from compressed gases for some applications.

Common fault four: bubbles appear in the pump discharge port

1. Check whether the pump diaphragm is ruptured.

2. Check the air tightness of the outer pressure plate.

3. Check the air tightness of the clamp band and the integrity of the O-ring and seal, especially the intake manifold location.

Common fault three: The pump does not run or runs slowly

1. Ensure that the gas inlet pressure is at least 0.3 bar (5 psi) higher than the starting pressure, and the pressure differential (the difference between the gas inlet pressure and the liquid outlet pressure) should be at least 0.7 bar (10 psi).

2. Check the gas inlet filter for debris (see the corresponding section in the Recommended Installation section for more details).

3. Check whether there is excessive gas leakage (bypass), usually characterized by worn air valves, guide needle valves or spindle seals/holes.

4. Disassemble the pump and check whether there are any obstructions or objects blocking the gas passage, which may cause restricted operation of the internal moving components.

5. Check whether the ball valve is stuck or not. Swelling may occur if the material being conveyed is incompatible with the elastomer components of the pump. Replace ball check valve and seal with new suitable elastomeric material assemblies. At the same time, when checking whether the ball valve is worn out, it is usually found that the ball valve is smaller in size and begins to get stuck in the valve seat. In this case, replace the ball valve and valve seat.

6. Check whether the inner pressure plate is damaged, as this will cause the air valve needle to be unable to move.

7. Remove the plug on the discharge port of the guide needle valve.