Seven solutions to the failure of the hottest regu

Seven solutions to the failure of the control valve

seven solutions to the failure of the control valve during operation

during the operation of the control valve, there are often problems such as jamming, and even some such problems occur when it is just put into operation. We have summarized some reasons and solutions for your reference

1. Cleaning method

the welding slag, rust, slag, etc. in the pipeline cause blockage or jamming in the orifice, guide part and balance hole of the lower bonnet, causing the valve core surface and guide surface to be strained and scratched, and the sealing surface to be indented, etc. This often occurs in the initial stage of new system operation and after overhaul. This is the most common fault. In this case, it must be disassembled for cleaning, and the slag must be removed. If the sealing surface is damaged, it should also be ground; At the same time, open the bottom plug to flush the slag falling into the lower valve cover from the balance hole, and flush the pipeline. Before putting into operation, the regulating valve shall be fully opened, and the medium shall flow for a period of time before being put into normal operation. Be sure to cut off the power supply for normal operation

2. External flushing method

it not only reflects the parameters. When using ordinary valves to regulate some media that are easy to precipitate and contain solid particles, it is often blocked at the throttle and guide, but also externally connected with flushing gas and steam at 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 regulating valve, so that the valve can operate normally

3. Install pipeline filter method

for small-diameter regulating valves, especially ultra-small flow regulating valves, the throttling clearance is very small, and there should be no little 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 medium. For the regulating valve with positioner, the positioner does not work normally, and the blockage of its gas path throttle is the most common fault. Because 1 Adjust the experimental device. When working with the positioner, you must deal with the air source. The usual method is to install the air filtration pressure reducing valve on the air source pipeline in front of the positioner

4, increase the throttling gap method

for example, the solid particles in the medium or the welding slag and rust washed out in the pipeline can not pass through the throttling port, resulting in blockage, jamming and other faults, so as to take steps to develop environmentally compatible and self-regulated The first step for military fake materials can be to use throttling parts with large throttling clearance - valve cores and sleeves with windowed and open throttling areas. Because their throttling areas are 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 into a "V" shaped valve core, or into a sleeve valve, etc. For example, a two seat valve in a chemical plant is often stuck. It is recommended to use a sleeve valve, and the problem is solved immediately

5. Medium scouring method

use the scouring energy of the medium itself to scour and take away things that are easy to precipitate and block, so as to improve the anti blocking function of the valve. Common methods are: ① change to flow closed type; ② Adopt streamlined valve body; ③ Place the throttle at the place where the erosion is most severe. When using this method, attention should be paid to improving the erosion resistance of the throttle material

6. The straight through method is changed to the angular method

the straight through method is inverted s flow, with complex flow path and many dead zones in the upper and lower cavities, providing a place for the sedimentation of the medium. Angular connection, the medium is like flowing through a 90 ℃ elbow, with good scouring performance and small dead zone, which is easy to be designed into a flow line. Therefore, if the straight regulating valve is used to cause slight blockage, it can be changed into an angle valve to use

7. The sleeve regulating valve used on the steam pipeline, if the gap between the valve core and the sleeve is too small, or different materials are used, it is likely to be blocked by heat due to different expansion coefficients. The clearance can be appropriately increased during processing (on the premise of meeting the flow control requirements) to prevent similar situations