Handwheel Override for Actuators
Lets an operator manually open or close an automated valve when instrument air or electrical power is unavailable, without removing the actuator.
How It Works
A declutchable gear train sits between the actuator output and the valve stem. In normal automatic operation the handwheel is disengaged and the actuator drives the valve directly. Engaging the clutch (pulling a knob or lever) locks the handwheel gear train to the actuator output shaft so turning the handwheel drives the valve manually. A spring-return-to-auto feature disengages the handwheel automatically once released, so automatic operation resumes without an operator having to remember to declutch it.
When Is It Required?
- -The valve must remain operable manually during an instrument air or power outage
- -Commissioning or maintenance requires manual stroking of the valve before the actuator's control signal is available
- -An ESD or safety valve needs a defined manual-reset path after a trip
Compatible Actuation Types
Compatible Valve Categories
Governing Standards
Codes shown are the governing references for this device class; confirm the specific edition and project spec before procurement.
Selection Considerations
- -The spring-return-to-auto feature is a safety-critical detail — verify it before relying on the actuator to resume automatic control unattended
- -Mounting interface (NAMUR or ISO 5211) must match the actuator, the same as any other top-mounted accessory
Commonly Specified In
FAQ
Why is the spring-return-to-auto feature on a handwheel override considered safety-critical?
Without it, an operator who manually declutches the handwheel during an outage could walk away and leave the actuator disconnected from the valve stem. If automatic control then resumes (air or power restored), the actuator would drive with no effect on the valve until someone notices and re-engages it. The spring-return disengages the handwheel automatically once released, so automatic control is never silently defeated.
Other Automation Accessories
Sourcing a Handwheel Override for Actuators?
We supply certified handwheel override for actuatorss matched to your actuator and valve, with documentation, under one PO.