What is the purpose of a handwheel on a control valve/switch valve? How to add it above
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This post was last edited by instrument_HKSC on 2018-2-27 at 16:48. What is the purpose of a handwheel on a control valve/switch valve? How to add it above? Please share any pictures if available, thank you
The handwheel is used to manually open and close the valve in case of a failure in the control valve. It is installed by the manufacturer at the time of production.
The image in this post shows how the handwheel is installed, and there is relevant information as well; it’s recommended to take a look. How to switch a control valve with a handwheel to manual mode? https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1551604 (Source: Haichuan Chemical Industry Forum)
It is used to prevent the valve from not being able to be opened or closed due to a failure in the control mechanism, allowing for manual operation in such cases
A handwheel is used to operate the valve when remote control is unavailable; valves that do not have a bypass line must be equipped with a regulating valve fitted with a handwheel.
If the signal is not provided in time at times, or if there is a problem with the relay, and the valve becomes stuck and cannot be controlled pneumatically, it must be switched to manual mode. Typical tower wall extraction valves are used during startup and shutdown operations; prolonged inactivity can lead to problems such as valve sticking, so it is necessary to manually turn them open to avoid hazards
If there is no control valve with a bypass, a handwheel should be provided so that manual operation via the handwheel can be used in case of a failure of the locator