Common Faults And Solutions Of Pneumatic Valves

Pneumatic valves are valve types that use compressed air as power to operate valves. They are an important part of industrial automation control. Therefore, their stability and reliability have a great impact on the entire production process. Therefore, when pneumatic valves fail, they need to be handled in time. The following will explain the common faults and solutions of pneumatic valves.

Pneumatic valves

Pneumatic valves

Fault 1: Pneumatic valve does not move

Phenomenon: The valve does not move at all and the indicator light is off.

Cause: This situation may be caused by reasons such as the air source not being turned on, the air source pipe being blocked, or the air source containing water and freezing.

Solution: First, check whether the air source is supplied normally, and secondly, clean or replace the filter to ensure that the air source pipe is unobstructed.

Fault 2: Pneumatic valve leakage

Phenomenon: After the valve is closed, there is still leakage of the medium.

Cause: Valve leakage is divided into two types: internal leakage and external leakage. Internal leakage is usually caused by poor sealing between the valve core and the valve seat, which may be caused by wear or corrosion of the valve core and valve seat, or insufficient strength of the actuator. External leakage may be caused by packing wear or loose bolts

Solution: To solve the internal leakage problem, the valve core and valve seat need to be ground or replaced. To solve the external leakage, the packing needs to be replaced or the bolts need to be tightened.

Fault 3: Cylinder Fault

Phenomenon: The fault is mainly manifested as air leakage, piston deformation or unstable movement.

Cause: These problems may be caused by dust accumulation inside the cylinder, poor lubrication or damaged sealing ring.

Solution: Clean the inside of the cylinder, lubricate the piston and replace the damaged sealing ring.

Fault 4: Positioner Fault

Phenomenon: Insensitive action and unstable output signal.

Cause: Positioner failure may be caused by circuit board problems, small slide valve damage or proportional valve failure.

Solution: This type of problem usually requires improving the sealing, improving the instrument air quality or replacing damaged parts.

Fault 5: Air source problem

Phenomenon: The valve action is weak and the valve action is unstable.

Cause: The air source is unstable and there is leakage.

Solution: Ensuring the stability and no leakage of the gas source is the key to solving this type of problem. The gas source processing device needs to be checked regularly and maintained in time.

Fault 6: Pneumatic valve blockage

Phenomenon: The valve is completely stuck and difficult to open.

Cause: Valve blockage is usually caused by foreign matter or adhesion in the valve.

Solution: The blockage in the valve core can be cleared by increasing the gas source pressure or using special tools.

Fault 7: Pneumatic valve vibration

Phenomenon: Abnormal vibration during valve operation.

Cause: Valve vibration may be caused by internal wear, corrosion or packing leakage of the valve stem.

Solution: Vibration problems require polishing the valve stem, replacing the packing or adjusting the valve fixing method.