1.Throttle port, guide position, lower valve cover balance hole blockage or flow port, guide position, lower valve cover balance hole blockage or blockage of the spool surface, guide surface strain scratches, abrupt surface indentation, etc.. This often occurs in the new commissioning system and the early stage of commissioning after overhaul. This is a common fault. In this case, it must be unloaded for cleaning, to remove the slag, such as the surface should also be grinded; at the same time, the bottom plug open to flush away the slag from the balance hole into the lower valve cover, and cleaning of the pipeline. Before conveying, let the gate valve completely open, the media flow for a period of time included in the normal operation.
2. Steam gate valve can be cleaned externally at the bottom of the lower valve cover blockage. When the gate valve is blocked or clogged, open the external gas or steam gate valve, you can complete the cleaning work without moving the gate valve, so that the valve works normally.
3. Gate valve throttle gap is small, no small slag in the medium. In case of obstruction, a filter is installed on the pipeline in front of the valve to ensure the smooth completion of the medium. Therefore, when working with a positioner, the air source must be dealt with. The general approach used is to install an air purification gate valve on the air source line before the positioner.
4. Failures such as blockage and clogging due to inability to pass the throttle. Due to the concentration of throttling area, due to the concentration of throttling area, throttling area concentration throttling area can be changed to open window, open spool and sleeve. If it is a single-seat valve, double-seat valve can be replaced with a plunger spool "V" spool shape, or changed to a sleeve valve, etc.. It is recommended that the problem be solved immediately after replacing the sleeve valve.
5. Gate valve media flushing method uses the medium itself to flush energy, flush and take away easy to precipitate, easy to block the items, thereby improving the valve discharge plug function. Gate valve to flow closed use; choose streamlined valve body; throttle port on the flushing serious place. When choosing this method, pay attention to improving the wear resistance of the throttling material.
6. straight up to change to angular method straight up for the inverted S flow, the flow path is cumbersome, the upper and lower capacitance cavity dead zone more, for the media sedimentation place. Angular connection, the medium is like flowing through the 90 ℃ bend, scouring performance is good, the dead zone is small, easy to design into the streamline. Therefore, the use of straight gate valve produces mild obstruction can be changed to the use of angular valves.