D81 Handwheel Overtorque Protectors

Manufacturer: Aunspach Controls

Operating torque is applied to either end of the D81. The torque is transmitted through the D81 mechanism and into the valve or actuator. If excessive torque is applied, the D81 drive will disengage and prevent damage. Operation is the same in either direction of rotation. Re-engagement is automatic with further rotation in either direction.


Model D81 Valve Overtorque Clutches prevent valve damage caused by use of excessive operating torque.


Valves and other equipment driven by manual gearboxes or electric actuators.

Capacities and Ranges

Trip Torque: 0 to 140 Nm
Higher and lower torque capacity models are available.

Operating temperature: -25 º to 100º C
Higher and lower temperature models are available.

Standard Max Bore : ø 30mm (ø 1.181″)
Standard Max Shaft : ø 30 mm (ø 1.181″)
Larger diameters available with adapter.


The unit is mounted directly on the valve, actuator or gearbox input shaft, between the actuator and hand wheel. No special tools or valve/actuator modifications are required.

Construction and Corrosion Protection

The mechanism is permanently lubricated and hermetically sealed inside a rugged steel housing, and is corrosion protected by fusion-bonded polyester.


No maintenance is required.

PDF Download

ACROGEARS D81 (971kb)

ACROGEARS_Aunspach V1.1 (1Mb)

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