Reasons why the valve does not close properly and solutions
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The common reasons why a valve does not close properly are as follows: (1) Impurities get stuck on the sealing surfaces, with debris accumulating at the bottom of the valve or between the valve disc and the seat; (2) The threads on the valve stem rust, preventing the valve from rotating; (3) The valve’s sealing surfaces are damaged, resulting in leaks of the fluid; (4) The connection between the valve stem and the valve disc is poor, causing the valve disc to be misaligned and fail to make tight contact with the seat. Methods for dealing with valves that don’t close properly I. Impurities stuck in the valve’s sealing surface Sometimes, a valve fails to close properly suddenly; this may be due to impurities getting stuck between the valve’s sealing surfaces. In such cases, one should not try to force the valve to close. Instead, it should be opened slightly more before attempting to close it again. Repeating this process usually resolves the issue; if not, further inspection is necessary. The quality and cleanliness of the medium should also be maintained. II. Rust on the valve stem threads In the case of valves that are usually in the open position, they may fail to close properly when closed occasionally, due to rust on the valve stem threads. In such cases, the valve can be opened and closed several times, while simultaneously tapping the bottom of the valve body with a small hammer; this will ensure that the valve closes properly, without the need for any grinding or repair work on the valve. III. Damage to the valve sealing surface In cases where the valve cannot be closed properly even after attempting to open and close it several times, it means that the sealing surface has been damaged – either due to corrosion or scratches caused by particles in the medium. Such situations require repair. IV. Poor connection between the valve stem and the valve disc. In this case, it is necessary to apply lubricant to the valve stem and the valve stem nut in order to ensure smooth operation of the valve when it is opened and closed. A proper maintenance plan is needed to enhance the maintenance of valves.
It is also possible that the valve position switch (electric on/off valve) or the mechanical limit settings are not appropriate.
Reasons why the valve does not close properly include: 1. Impurities are stuck in the sealing surface. 2. The valve stem threads are rusted. 3. The sealing surface is damaged. 4. Poor connection between the valve stem and the valve disc. Solution: 1. If debris is stuck: slightly open the valve and then close it tightly, or clean the medium. 2. Rust on the valve stem: Operate the valve repeatedly and tap the bottom of the valve body. 3. Sealing surface damage: The sealing surface needs to be repaired or replaced. 4. Poor connection: Apply lubricant and ensure the connection is proper. Regular maintenance is also carried out simultaneously. .
There are also reasons related to valve selection; if the torque of the valve’s actuator is too low, it will still not be able to close properly when pressure builds up in the pipeline.
The main reason why valves do not close properly is caused by fluid impurities.
The main factor is a significant test of the experience of the operation and maintenance personnel
Yes, the operator’s actions and process control are particularly important. For example, if temperature changes cause the packing gland to be too tight, loosen the packing appropriately during operation, and then re-tighten it after the switching operation is complete. These fall under the user’s operational actions. Process control of materials: knowing full well that impurities cause the valves to not close properly, yet continuing to apply force only results in damage to the valves. If the switching action is repeated, flushing with fluid can wash away the impurities. ，，，，，。