VALVE TO STOP A FLOW

摘要

A valve for shutting off a flow having a housing wherein a plug member is movable between "on" and "off" terminal positions by means of a thread; a rotary drive which is switchable off with time delay in the "off" terminal position of the valve; a resilient member for limiting an increase in torque generated by kinetic energy of the rotary drive in the "off" terminal position; and a torque control for the rotary drive includes means defining a range of rotation of the rotary drive in both directions of travel thereof, the entire range of rotation corresponding to a stroke of the plug member and being subdivided into a starting range beginning at one terminal position and ending before a new terminal position is reached as well as into the remaining range; the rotary drive having an available starting torque (break-away torque), taking into consideration the tolerance limit of the power supply in the starting range downwardly, which is at least 10% higher than the largest torque applicable by the rotary drive, taking into consideration the tolerance limit of the power supply in the remaining range upwardly.