Questions about control valves
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In the application of control valves, under what circumstances is it necessary to have a handwheel? Please explain!
When there is no bypass valve, a handwheel should generally be provided to facilitate manual operation of the control valve in case of a problem with the instrument air.
The last edit to this post was made by waneng on 2017-1-9 at 14:37. Control valve handwheel: 1. When there are no shut-off valves in front of or behind, or no bypass valves, it is recommended to use a handwheel for the control valve； 2. It facilitates manual operation by process operators in the event of a gas supply failure, thereby meeting temporary process requirements ； It facilitates the operation of processes in containers such as tower bottoms during testing scenarios involving pressure retention or release while driving the equipment. 3. It facilitates debugging and maintenance by instrument maintenance personnel. If the control valve is part of a SIS or critical interlock, it should in principle not be equipped with a handwheel or manual operating device; in such cases, the design specifications must be strictly followed. The handwheel cannot serve as a mechanical limit for the valve.
I agree with the view from the second floor; it’s not really a matter of whether I agree or not. We do this in practice as well, and we endorse this concept.
Was this decided by your instrumentation specialty?