Help me analyze whether this phenomenon with the control valve is normal or a problem on the customer’s end
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It’s an electric control valve that uses steam to heat water for employees’ bathing; it operates by using a thermometer and a PID controller to maintain a set temperature. However, this type of valve has a strange problem: no matter which manufacturer produces it, its lifespan is only one year. The cheaper ones are from Zhejiang, while those from better-known manufacturers are still not as reliable as those produced by Wuxi Industrial Equipment or Wuzhong Valve Factory. Now, the customer has told me that there is a leakage issue – I can hear a hissing sound coming from the valve. When there is a leak, the water temperature rises. Some people say that control valves are only meant for regulating flow, and that valves designed to cut off flow would be better. I’m puzzled as to why there is constant leakage; perhaps the customer’s requirements are unrealistic
It’s normal for your system to leak air, as the control valve will activate whenever there is a temperature deviation. Having such a control system just for taking a bath is way too fancy; it’s overkill. In fact, a shut-off valve would be sufficient – it can simply stop the flow when the temperature reaches a certain level
It is normal for a control valve to leak after being in use for some time; if leakage occurs, it needs to be repaired.
It’s normal for the control valve not to close tightly; it’s necessary to use an electric door or a manual gate valve to achieve closure
Control valves used to regulate steam generally require the valve core and seat to be hardened (for example, by welding stainless steel on them). It is likely that the valve core and seat in your case have not been hardened, and as a result they were eroded by the steam after some time, leading to internal leakage.
The control valve breaks after just one year of use; there are two possible reasons for this. One is an incorrect selection – for example, a control valve that isn’t resistant to high temperatures was used to control steam. The other reason is that the quality of the control valve is very poor. Nowadays, many private companies purchase components and assemble them on their own before selling them to customers, without conducting any performance tests. It’s already quite good if such a valve breaks after just one year of use.
Have you removed the control valve to check the valve stem and the sealing surface of the valve seat for any signs of erosion?
First, is it an internal leak or an external leak? Can you hear a sound from the internal leak? If it’s an external leak, that has nothing to do with the issue you mentioned, right? It might be an internal leak; however, the extent of the leak matters as well. New valves can also leak after being pressurized, and the degree of leakage varies depending on the level of leakage. If problems arise only after long-term use, it indicates that the valve core and seat have been severely eroded and can no longer be pressed tightly together. It depends on the structure of the valve stem; could trying to increase the preload by adjusting the length of the valve work?
Code error: Adjust the valve stem length. Is it also possible that impurities are stuck between the valve core and the valve seat, causing it to not close properly? . .
Where is the leak? Is it a connection flange or something else between the valve stem and the valve seat? If there is a leak, the manufacturer should be called to take a look; it’s impossible for the control valve to shut off completely, so a manual or electric gate valve needs to be installed in front of or behind it
Try a different solenoid valve; it’s cheap and effective.