1. Cleaning method: the welding slag, rust and slag in the pipeline are blocked or stuck in the orifice, guide position and balance hole of lower valve cover, causing the surface of valve core and guide surface to be pulled and scratched, and the sealing surface to be indentation, etc. This often occurs at the beginning of new operation system and after overhaul. This is the most common failure.

2. External flushing method: when ordinary valves are used to regulate the medium which is easy to precipitate and contains solid particles, it is often blocked at the throttle port and guide position, and flushing gas and steam can be connected at the bottom plug of lower valve cover. When the valve is blocked or stuck, open the external gas or steam valve to complete the flushing work without moving the regulating valve, so that the valve can operate normally.

3. Install the pipeline filter method. For the small-diameter regulating valve, especially the ultra-small flow regulating valve, its throttling clearance is very small, and there should not be a little slag in the medium. In case of blockage, it is better to install a filter on the pipeline in front of the valve to ensure the smooth passage of media. The regulator valve with positioner works abnormally, and the most common failure is the blockage of its air throttle. Therefore, when working with positioner, the air source must be handled well. The usual method is to install air filter pressure reducing valve on the air source pipeline in front of the positioner

4. Increase the throttling clearance method, such as solid particles in the medium or welding slag and rust washed out in the pipeline, which can not pass through the throttling orifice and cause blocking, jamming and other faults. The throttling parts with large throttling clearance can be used instead - the throttling area is the valve core and sleeve with windows and openings. Because the throttling area is concentrated rather than distributed in a circle, the faults can be easily eliminated. If it is a single seat valve or a double seat valve, the plunger shaped valve core can be changed into a V-shaped valve core or a sleeve valve. For example, a double seat valve is often stuck in a chemical plant. It is recommended to use sleeve valve instead, and the problem will be solved immediately.

5. The medium flushing method, using the flushing energy of the medium itself, scours and takes away the things that are easy to precipitate and block, so as to improve the anti blocking function of the valve. The common methods are: ① changing to flow closed type; ② adopting streamline valve body; ③ putting the orifice at the place with the most severe scour, so we should pay attention to improving the erosion resistance of the throttle material.

6. The straight through method is changed to the angle method, and the straight through method is inverted s flow. The flow path is complex, and there are many dead zones in the upper and lower cavities, which provides a place for the precipitation of the medium. Angle connection, medium as if flowing through 90 ℃ elbow, good scour performance, small dead zone, easy to design into flow line. Therefore, it can be changed to angle valve when the through regulating valve is slightly blocked.