Setting the end stops for manual operation, 1 worm gearboxes on butterfly valves, Manual operation 12 – AUMA Part-turn gearboxes GS 50.3 - 250.3, primary reduction gearings VZ 2.3 - 4.3_GZ 160.3 - 250.3 User Manual
Page 12: For manual operation 12, Worm gearboxes on butterfly valves