Model D80 Overtorque Clutch prevents potential operator injury and valve damage caused by excessive operating torque. The Clutch is typically mounted between the handwheel and manual or electric actuator. Operating torque is transmitted from the handwheel through the D80 to the actuator. Damaging torque is not transmitted. Further handwheel rotation resets trip torque. Units are shipped pre-calibrated and ready to mount. The mechanisms are permanently lubricated and hermetically sealed. No maintenance required. They are corrosion protected by fusion-bonded epoxy and stainless steel fasteners with enamel topcoat for ultraviolet protection.