Transtork make Manual Over-Ride Worm Gear boxes are used with pneumatic, hydraulic and back-drivable electric actuators. These products are sandwich mounted as part of an automated valve package to provide manual operation to the valve and manually over-riding pneumatic actuators in case of loss in plants air supply, power gas, hydraulic fluid power or electricity occurs. These gear boxes are engineered and designed for higher efficiencies and lower efforts on hand wheel which are used with valves and dampers for quarter turn rotary applications that comes with thirteen different frames and spur combinations to provide output torque range from 60 to 5,000 Nm. These gearboxes are designed with standard ISO 5211 mounting dimensions for mounting to valve & actuator.