Multi-turn gearboxes can be formed by combining multi-turn actuators SA ... with AUMA worm and bevel gearboxes to increase the torque or to reposition the output shaft. The gearboxes can of course also be used on manually operated valves.
OPEN-CLOSE or modulating duty
Class A: OPEN-CLOSE duty. The actuator is required to drive the valve through its entire travel from the fully open position to the fully closed position or vice versa.
Class B: Inching/positioning or positioning duty. The actuator is required to occasionally drive the valve to any position (fully open, intermediate and fully closed).
Class C:Modulation or modulating duty. The actuator is required to frequently drive the valve to any position between fully open and fully closed.