Abstract: A heat sealing assembly, for sealing thermoplastic film, comprising first and second jaws, an electrical impulse heat sealing element, electrical terminals, and an electrical and thermal insulating material between the first jaw and the heat sealing element, said heat sealing element being removably connected to said electrical terminals, at least one of said jaws being capable of transverse motion and adapted to collapse a tubular film made from said thermoplastic film and passing between said jaws, wherein said element has at each end an electrical contact male plug oriented at about 90 degrees angle from said element, said plugs being parallel to each other and having a shape which allows each to be received in correspondingly shaped sockets, said sockets being held by spring means adapted to apply force in tension to said element when said plugs are in said sockets, said plugs being adapted to fit into said sockets when said spring means are deflected toward said element, and wherein securing means for pr

Abstract: A valve for injecting or ejecting fluid to or from a fluid stream flowing in a pipe includes a valve body connected between abutting flanges in the pipe. The body has a through passage intersecting the pipe with seating assemblies located in each end of the through passage which cooperate with a stem assembly to provide communication between a port, the valve body and the pipe.