Control valve in use sometimes due to the principle of the media, resulting in the control valve stuck or blocked, can not work, this time, it should be avoided, or its treatment, the following describes several ways for reference purposes only : 1) cleaning method Pipe in the welding slag, rust, slag, etc. in the throttle, guide parts, under the valve cover to balance the hole caused by blockage or stuck so that the valve surface, guide surface tension and scratches, seal Face indentation and so on. This often occurs in the early delivery of new delivery systems and overhauls. This is the most common failure. In this case, you must uninstall the cleaning, remove the slag material, such as the sealing surface is also damaged should be ground at the same time the bottom plug to open to flush away from the balance hole into the valve cap slag material, and the pipeline Rinse. Put into operation before the valve is fully open, medium flow into the normal operation after a period of time. 2) External scouring method For some easily sedimentation, medium containing solid particles using ordinary valve adjustment, often in the throttle, the guide block, can be flush at the bottom of the valve cover flushing gas and steam. When the valve is clogged or stuck, open the external gas or steam valve, you can complete the flushing work in the case of the valve does not move, so that the valve normal operation. 3) The installation of pipe filter method on the small-caliber control valve, especially the ultra-small flow control valve, the throttle clearance is very small, medium can not have a little slag material. In this case of blockage, it is best to install a filter on the valve before the pipeline to ensure the smooth passage of media. Control valve with locator, locator is not working properly, the air passage choke plug is the most common failure. Therefore, with locator work, you must handle the gas source, the commonly used approach is to install the air filter regulator in front of the gas locator 4) Increase the throttle gap method such as the medium of solid particles or pipes Washes off the welding slag and rust, etc. due to over throttle can cause blockage, stuck and other failures, can be used to throttle large gap throttling pieces - throttle area for the window, the opening of the spool, sleeve Tubes, because of their concentrated throttle area rather than their circumferential distribution, can easily be ruled out. If it is single, two-seater valve plunger can be changed to "V" -shaped spool, or into the sleeve valve. For example, a chemical plant often have a double-seat valve stuck, it is recommended to switch to sleeve valve, the problem was resolved immediately. 5) Medium scouring method uses the scouring energy of the medium itself to scour away and remove the easily sedimentable and clogged things, so as to improve the anti-clogging function of the valve. Common methods are: ①closed for the flow of closed-type use; ② the use of streamlined body; ③ the throttle placed in the erosion of the most powerful, using this method should pay attention to improve the erosion-resistant materials, parts erosion. 6) Straight through to the angle method Straight through the inverted S flow, the flow path is complex, the upper and lower cavity dead zone, provides a place for the precipitation of the medium. Angular connection, like 90 ° elbow flow through the medium, erosion performance, small dead zone, easy to design streamlined. Therefore, the use of straight through the control valve can be slightly blocked when the valve can be changed to use.