A valve fixing mechanism for fixing protruding walls of valve housings of adjacent gate valves to a chamber in a fixing space defined between the valve housings includes a support member fixed to the chamber in middle part of the fixing space and a pair of lever members arranged on both sides of the support member. The pair of lever members each include fulcrum part, load part, and effort part arranged in that order from the middle part of the fixing space to an opening at either end of the fixing space. The fulcrum part is supported by the support member, and a force is applied to the effort part by a fixing operation bolt, so that both the load part and the effort part press the protruding walls of the valve housings against the chamber.

A valve actuator assembly having an actuator housing coupled to a bonnet and a housing lid. A hydraulic cylinder is positioned within the actuator housing and directly coupled to the bonnet. A piston is positioned within the hydraulic cylinder and coupled to a spring lifter assembly and a spring is positioned within the actuator housing and having a first end and a second end, the first end being coupled to a lower surface of the housing lid, and the second end being coupled to the spring lifter assembly. An operating stem is coupled to the piston and positioned in a channel extending through the bonnet to a valve body assembly.

A valve actuator assembly having an actuator housing coupled to a bonnet and a housing lid. A hydraulic cylinder is positioned within the actuator housing and directly coupled to the bonnet. A piston is positioned within the hydraulic cylinder and coupled to a spring lifter assembly and a spring is positioned within the actuator housing and having a first end and a second end, the first end being coupled to a lower surface of the housing lid, and the second end being coupled to the spring lifter assembly. An operating stem is coupled to the piston and positioned in a channel extending through the bonnet to a valve body assembly.

A vacuum valve including a closure element (3) and a valve housing (1) with a valve opening (4) and an interior (2) in which the closure element (3) is arranged, the closure element resting against a valve seat (6) surrounding the valve opening (4) in the closed state of the vacuum valve. The valve housing (1) has a housing wall (19) made of sheet metal, the housing wall delimiting the interior (2) and being provided with a window opening (20) in order to form the valve opening (4). The valve opening (4) is surrounded by a flange ring (21) that can be connected to a connection flange (28) of a vacuum unit (27) via screw connections, the vacuum unit having an interior and being attachable to the vacuum valve. The flange ring (21) has the valve seat (6) on which the closure element (3) is placed in the closed state of the vacuum valve.

A valve actuator assembly having an actuator housing coupled to a bonnet and a housing lid. A hydraulic cylinder is positioned within the actuator housing and directly coupled to the bonnet. A piston is positioned within the hydraulic cylinder and coupled to a spring lifter assembly and a spring is positioned within the actuator housing and having a first end and a second end, the first end being coupled to a lower surface of the housing lid, and the second end being coupled to the spring lifter assembly. An operating stem is coupled to the piston and positioned in a channel extending through the bonnet to a valve body assembly.

A valve actuator assembly having an actuator housing coupled to a bonnet and a housing lid. A hydraulic cylinder is positioned within the actuator housing and directly coupled to the bonnet. A piston is positioned within the hydraulic cylinder and coupled to a spring lifter assembly and a spring is positioned within the actuator housing and having a first end and a second end, the first end being coupled to a lower surface of the housing lid, and the second end being coupled to the spring lifter assembly. An operating stem is coupled to the piston and positioned in a channel extending through the bonnet to a valve body assembly.