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Common Faults and Maintenance of Pneumatic Ball Valve


Release time:

2021-07-12

Pneumatic ball valve is an important actuator in industrial automation control system. Pneumatic ball valve is based on the movement of the valve disc around the axis of the valve stem for the rotation of the valve. The change of the valve seat opening is proportional to the stroke of the valve flap. It is mainly used to cut off or connect the medium in the pipeline, and can also be used for fluid conditioning and control. It is a pipeline pressure element for industrial automation process control.

Common Faults and Maintenance of Pneumatic Ball Valve

Pneumatic ball valveIt is an important actuator in industrial automation control system. Pneumatic ball valve is based on the movement of the valve disc around the axis of the valve stem for the rotation of the valve.
The change of the valve seat opening is proportional to the stroke of the valve flap. It is mainly used to cut off or connect the medium in the pipeline, and can also be used for fluid conditioning and control. It is a pipeline pressure element for industrial automation process control.
Pneumatic ball valves typically suffer from a safety valve, a tension spring between the stem and a valve mounted on the actuator acts to reciprocate in one of its gates urging the orientation of the gate, which may be closed by the body, and the control fluid is applied to the piston in the stem. The actuator overcomes the tension spring force and then remains in the other orientation usually on, so it is maintained for a long time as a control condition.
When this structure valve is abandoned at a large depth, and the pressure of the body is much lower than the pressure of the surrounding sea surface, the tension spring of the pneumatic ball valve is necessary to meet the large, and the force to close the valve cannot meet the position of the failure of the moving door because of the pressure of the body. It can happen in extreme cases. Then reducing the size of the actuator increases the depth rating of the valve.
Exclusion method: By pneumatic ball valve fault, which is included in this category, the valve body has a traditional valve that passes through the structure and a cavity that intersects the door, the cavity opens and closes between the positions, and is responsible for moving these positions between the doors of the actuator. As is also the case in this type of valve, the actuator contains a bonnet mounted on the valve body with the valve stem connected to the other valve.
Maintenance Method
1. As long as the pressure before and after the ball valve is removed, the ball valve can be disassembled and differentiated.
2. In the process of differentiation and reassembly of ball valves, it is necessary to maintain sealed parts, especially non-metallic parts, such as O-rings and other parts.
3. It is necessary to tighten the bolts symmetrically, gradually and evenly when reassembling the ball valve body.
4. The cleaning agent should be compatible with the rubber parts, plastic parts, metal parts and operating media (such as gas) in the ball valve. When the operating medium is gas, gasoline (GB484-89) can be used to clean metal parts. Non-metallic parts are cleaned with pure water or alcohol.
5, the differentiation of individual parts can be cleaned by immersion. Metal parts with undifferentiated non-metal parts can be scrubbed with clean fine and clean silk cloth impregnated with cleaning agent (to avoid fiber falling and adhering to parts). All grease, dirt, glue and dust adhering to the wall shall be removed during cleaning.