When some media that are easy to precipitate and contain solid particles are adjusted by ordinary valves, they are often blocked at the throttle and guide, and the gas and steam can be flushed at the bottom of the lower bonnet. When the valve is blocked or jammed, open the external gas or steam valve to complete the flushing operation without moving the regulating valve to make the valve operate normally.
Installation of pipe filter method: For small-diameter regulating valves, especially ultra-small flow regulating valves, the throttle gap is very small, and there should be no slag in the medium. In case of blockage, it is best to install a filter on the pipe in front of the valve to ensure the smooth passage of the media. With the regulating valve used by the positioner, the positioner does not work properly, and the blockage of the air passage throttle is the most common fault. Therefore, when working with the positioner, the air supply must be handled. The usual method is to install an air filter pressure reducing valve on the air supply line before the positioner.
If the solid particles in the medium or the slag and rust that are washed away in the pipeline cannot be blocked or jammed due to the throttle opening, the throttle with a large throttle gap can be used instead. Valves and sleeves of windows and openings can be easily eliminated because their throttle areas are concentrated rather than circumferentially distributed. If it is a single or double seat valve, the plunger valve core can be changed to a "V" shaped valve core, or changed to a sleeve valve. For example, if a chemical plant has a double seat valve that is often stuck, it is recommended to use the sleeve valve to solve the problem immediately.
Using the scouring energy of the medium itself, scouring and taking away things that are easy to precipitate and easily clog, thereby improving the anti-blocking function of the valve.
Common methods are: 1 changed to flow-type use; 2 uses streamlined valve body; 3 puts the throttle port to the most powerful part of the flushing, and this method should pay attention to improve the erosion resistance of the material of the throttle piece. Straight through to the angle method Straight through for the S flow, the flow path is complex, the upper and lower chambers have more dead zones, providing a place for the precipitation of the medium. The angular connection, the medium is like flowing through the 90 °C elbow, the scouring performance is good, the dead zone is small, and it is easy to design into a streamline shape. Therefore, the use of a straight-through regulating valve can be changed to an angle valve when it is slightly blocked.