Control valve handwheel
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In what situations should control valves be equipped with handwheels, and in which situations not? What specific factors need to be considered?
Let me do it first. If the area where the valve is located is dangerous and access is not allowed for operators, then a handwheel cannot be used...
It should be the process engineering team that tells the instrumentation team whether a handwheel is required or not
Consider the case of a handwheel: 1. In particularly important situations. 2. When the control valve does not have a bypass line. 3. Or, although there is a bypass line, the pressure difference before and after the control valve is relatively large, making it unsuitable to use the bypass line for regulation for extended periods of time. A handwheel may not be necessary in other situations
Esd valves do not require a handwheel
1. A large bore size requires a handwheel mechanism. 2. Those without a secondary line need to use a handwheel
Whether to include a handwheel is determined from the perspective of safe production processes; that is, in case the control of the control valve fails, it is possible to manually open and close the valve to ensure production safety.
The instrumentation team only needs to be aware of this issue; it is actually the process engineering team that should make the requests. If they say it’s necessary, then it will be included; if not, it won’t be added.