The carbon black exhaust butterfly valve will not open after being closed for a long time! !
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The butterfly valve installed on the carbon black exhaust vent pipeline was originally of the 600S type manufactured by Wuxi Tools; it was later replaced with a butterfly valve from Jiangnan Valves. During normal production, this valve remains closed to prevent any exhaust； If starting or stopping the machine, it is necessary to open the vent to adjust the exhaust pressure when the load changes. Since the carbon black exhaust contains water and H2S, and the temperature is 200 degrees, if the valve remains open for an extended period, rust will form on both sides of the butterfly valve shaft, eventually preventing it from moving. Increasing the air supply or knocking on the enclosure doesn’t work either. Sometimes it gets stuck – it can’t be turned on nor off, and even when stopped, it can’t be resolved in a short period of time. It can only be removed during long-term maintenance, and the shaft ends on both sides are lubricated with a loosening agent to make them movable. Does anyone have any good solutions for this type of operating condition? It’s really unbearable :(
If it must be opened, keep the air supply connected first; then you can use a large clamping plate to turn the valve stem, and it usually can be opened this way.
Now there are manufacturers capable of solving the rusting problem between the shafts and bushings; another solution is to add a reverse blowing mechanism.