The gate valve does not close all the way
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The old valves leaked during pressure testing; upon disassembly and inspection, it was found that the valve plates did not seat properly. Several valves were affected in this way. It’s difficult to measure the valve plate with an inclined edge; I plan to use red lead to see where it’s stuck. Have any experts encountered this situation? What are the causes, and how can it be resolved?
This problem is caused by excessive corrosion at the connection between the valve plate and the valve stem inside the valve. It is best to restore it to its original state by patch welding and grinding. Additionally, clean the guide slides of the valve body and any residual structures at the bottom. The most common cause of valve jamming is misalignment between the slide rail and the edge of the valve disc, which leads to jamming. The valve stem limit device cannot be ruled out either. It would be best to send a video for easier discussion.
The answer upstairs is correct! The card is stuck; it’s possible that there’s an object stuck in the guide card! The most straightforward thing to do is to check first! If not, then we need to consider the residue and wear on the sealing surfaces of the gate and valve seat! Generally, gate valves specify a wear stroke! If it wears out, it will just fall down! Let’s take it apart and have a look! The most intuitive!
It has been disassembled; no foreign objects were found stuck in the guide rails or at the bottom. It seems that the valve plate has deformed, but it’s not possible to confirm this through measurement
If it has already been disassembled, it’s best to analyze the results! Use the removed valve stem to hang the gate and try to lower it into that valve body. If it still gets stuck as you said, and the valve body guide isn’t deformed, then it’s the gate plate that’s deformed; in that case, the only option is to replace the gate plate! However, the probability of deformation of the gate plate is generally low! Our guidance is quite loose! ! Zhang will also shake!