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Common pneumatic valve products include pneumatic control valves, pneumatic wafer-type hard-sealed butterfly valves, pneumatic flanged hard-sealed butterfly valves, pneumatic flanged multi-layer metal hard-sealed butterfly valves, reciprocating pneumatic diaphragm valves, and CV3000 series pneumatic valve products; among these, the pneumatic control valve is one of the more important types. Such products are prone to blockages due to improper maintenance during use. The following are several preventive measures: 1) Cleaning method – Weld slag, rust, and debris in the pipelines can cause blockages or jams at the throttle ports, guide sections, and balance holes on the lower valve cover, which in turn can lead to scratches and damage on the surface of the valve core and its guide surfaces. In such cases, it is necessary to remove the component for cleaning in order to get rid of debris; if the sealing surface is damaged, it should also be ground ； At the same time, open the bottom plug to flush out the debris that has fallen from the balance hole into the lower valve cover, and to clean the pipelines. Before putting it into operation, open the control valve fully; allow the medium to flow for a while before proceeding with normal operation. 2) External flushing method: When using ordinary valves to regulate media that tend to precipitate and contain solid particles, blockages often occur at the throttling ports and guide areas; in such cases, flushing gas and steam can be introduced at the bottom plug of the lower valve cover. When the control valve becomes clogged or stuck, opening the external gas or steam valve allows for flushing to be carried out without moving the control valve itself, thereby restoring its normal operation. 3) Pipe filter installation: For small-diameter control valves, especially those with extremely low flow rates, the throttling gap is very small; even a tiny amount of debris in the fluid can cause blockages. It is advisable to install a filter on the pipeline before the valve to ensure smooth flow of the fluid. For control valves used with positioners, when the positioner does not function properly, the most common fault is a blockage in the air supply throttle. 4) The method of increasing the throttling gap: Solid particles in the fluid, or welding slag and rust that get washed away in the pipes, can cause blockages and other problems due to their inability to pass through the throttling opening. In such cases, it is possible to use throttling elements with a larger throttling gap – valve cores or sleeves with window-like or open-shaped throttling areas. Since the throttling area is concentrated rather than distributed circumferentially, such problems can be easily resolved. For single or double-seat valves, the plunger-type valve core can be replaced with a valve core having a “V”-shaped port, or it can be changed to a cartridge valve or similar. 5) Medium scouring method: Utilizes the scouring energy of the medium itself to wash away and remove substances that tend to precipitate or cause blockages, thereby enhancing the valve’s resistance to blockage. Common methods include: ① modifying it for use in a flow-closed configuration ； ②Use a streamlined valve body ； ③Place the throttle at the area most subject to erosion; when using this method, it is important to enhance the erosion resistance of the throttling element. 6) Changing from straight-through to angular flow method: The straight-through configuration involves an inverted S-shaped flow pattern, resulting in a complex flow path and numerous dead zones in the upper and lower chambers, which provide areas for the deposition of the medium. Angular connection: the medium flows as if through a 90° elbow, offering good scouring performance, a small dead zone, and allowing for easy design in a streamlined shape.