◆ Cleaning method
Welding slag, rust, slag, etc. in the pipeline of the electric control valve cause blockage or jam in the throttle, guide part, and balance hole of the lower bonnet, causing strain and scratches on the valve core surface, guide surface, and sealing surface Produce indentation and so on. This often occurs in the initial commissioning of new systems and after major repairs. This is a common fault in Zui. In this case, it must be unloaded and cleaned to remove the slag. If the sealing surface is damaged, it should be ground. At the same time, the bottom plug should be opened to wash away the slag falling into the lower valve cover from the balance hole, and the pipeline Perform flushing. Before putting it into operation, let the regulating valve be fully opened, and the medium will flow for a period of time before being brought into normal operation.
◇ External flushing method
When ordinary valves are used to adjust some media that are easy to precipitate and contain solid particles, they are often blocked at the orifice and guide. The flushing gas and steam can be externally connected to 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 and make the valve operate normally.
◆ Install pipe filter method
For small-diameter control valves, especially ultra-small flow control valves, the throttle gap is extremely small, and there should be no slag in the medium. In case of blockage in this situation, Zui installed a filter on the pipe before the valve to ensure the smooth passage of the medium. For the regulating valve used with the positioner, the positioner does not work properly, and its air passage orifice is blocked is a common fault in Zui. Therefore, when working with a positioner, the air source must be handled. The usual method is to install an air filter pressure relief valve on the air source line before the positioner.
