1. Cleaning method: The welding slag, rust, slag, etc. in the pipeline cause blockage or jam in the throttle hole, the guiding part and the balance hole of the lower bonnet, causing strain and scratches on the curved surface of the valve core and the guiding surface. In this case, it must be unloaded for cleaning, remove the slag, if the sealing surface is damaged, it should be ground; at the same time, the bottom plug is opened to wash off the slag falling into the lower bonnet from the balance hole, and the pipeline Rinse. Before commissioning, let the regulating valve open completely, and the medium will flow into the normal operation after a period of time.
2, medium flushing method: the use of the medium's own flushing energy, scouring and taking away things that are easy to precipitate, easy to block, thereby improving the valve's anti-blocking function. Common methods are:
a changed to flow closed type;
b using a streamlined valve body;
c Place the orifice at the most scouring point. Use this method to pay attention to improve the erosion resistance of the throttle.
3, straight through the angle method: straight through the inverted 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.
4. Increase the throttling gap method: the solid particles in the medium or the slag and rust that are washed away in the pipeline can not be blocked or stuck due to the throttle, and the section with large throttle gap can be used instead. Flow element—The throttle area is a window opening, an open type valve core, and a sleeve. Since the throttle area is concentrated rather than circumferentially distributed, the fault can be easily eliminated. 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.
5. External scouring method: When some mediums 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 regulating 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.
6. Installation of pipeline filter method: For small diameter regulating valve, especially ultra-small flow regulating valve, the throttle gap is very small, even if there is a little bit of slag in the medium will be blocked, it is best to install a pipe on the front of the valve. Filter 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.
