Double plate large stop valve - is actuated by sliding bar with pivot links to plates either side

摘要

The stop valve has a housing for connection to a pipe and with two internal parallel seats against which plates are pressed by a mechanism between the latter. Plates and mechanism are inserted in the housing via an opening with cover. The mechanism incorporates a bar (17) passing through a packing seal (8) in the housing and moved to and from by an external actuator in a plane parallel to the seats and between them. At the bottom, the bar is coupled to the plates (22) by pivot links (19). The hinge points between bar, links and plate lie on a line which becomes steadily straighter as the plates are pressed home.