During the use of fluorine lined regulating valve, sometimes due to the principle of medium, the fluorine lined regulating valve will be stuck or blocked, unable to work normally. At this time, it should be avoided or treated. The following several methods are introduced for reference only:
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, which causes the surface of valve core and guide surface to be pulled and scratched, and the sealing surface to be pressed. This often occurs at the beginning of new operation system and operation after overhaul. This is the most common failure. In this case, it is necessary to remove the slag for cleaning. If the sealing surface is damaged, it is also necessary to grind it. At the same time, open the bottom plug to flush out the slag falling into the lower valve cover from the balance hole and flush the pipeline. Before putting into operation, the fluorine lined regulating valve shall be fully opened, and the medium shall be put into normal operation after flowing for a period of time.
External scour method
When the ordinary valve is 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 the flushing gas and steam can be connected outside the bottom plug of the 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 fluorine lined regulating valve, so that the valve can operate normally.
Installation of pipeline filter
For the small-diameter fluorine lined regulating valve, especially for the ultra-small flow fluorine lined regulating valve, the 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 fluorine lined regulating 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 positioned
Method of increasing throttle clearance
For example, the solid particles in the medium or the welding slag and rust washed out in the pipeline can not pass through the orifice, resulting in 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 circular distribution, 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.
Medium scour method
The flushing energy of the medium itself is used to wash and take 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.
Change straight to angle method
The direct flow is reverse 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 deposition of media. 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 using straight fluorine lined regulating valve to produce slight blockage.