Discussion on issues with Siemens M40 valve positioners
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The Siemens M40 low-temperature resistant valve positioner is used outdoors in Ordos, where the temperature is around -30°C; in such conditions the positioner does not function. It starts working once electric heating is applied. There is an online dew point tester to monitor the gas supply. Have you encountered a similar situation?
Siemens M40 low-temperature valve positioner? I’ve never heard of it, nor have I used it. I have been using Siemens PS2 series valve positioners, around four to five hundred of them. The outdoor temperature is around -30 degrees, the same as yours, and I have not encountered any problems due to low temperatures. It is important to control the dew point of the gas used by the instruments; if the lowest outdoor temperature is -30 degrees, then the dew point of the gas used by the instruments should be kept below -50 degrees to prevent condensation in the gas supply.
The M40 model is designed for low-temperature use, operating in temperatures ranging from -40 to 80°C. The dew point meter also functions fine; it’s just not able to operate properly. Adding electric heating to the tube connections resolves this issue
Try replacing the locator to see if it’s the locator that can’t handle low temperatures
Can valves and pressure reducing filters withstand low temperatures? The fact that the optical locator can withstand low temperatures does not guarantee that the entire valve set can do the same