Armature control of fluid flow in pipeline

摘要

The sealing device (32) has at least a second element (56), which seals against the closure element (30) and/or the drive unit (40,44), and also the housing (12). It is arranged at a distance from the first element (54) to create an intermediate chamber (62).The sealing device has at least one opening (66), which runs from the intermediate chamber, between the first seal element and the second, to the outside of the housing.