Remotely operable hermetically sealed plug valve

A hermetically sealed valve adapted to be placed in flow communication with a fluid line, comprising:

• a housing having a fluid inlet and a fluid outlet and an intermediate chamber in flow communication therewith forming a flow path through the valve, said housing adapted to be hermetically coupled in flow communication with the fluid line, said housing including a pair of spaced concentric cylindrical surfaces and an interconnecting valve seat;
• a plug being positionable in the chamber of the housing in operative relationship with the fluid inlet and fluid outlet between open and closed positions, said plug having a through opening therein for opening the flow path from the inlet to the outlet when in the open position and for blocking the flow path when in the closed position, said plug further including a pair of cylindrical spaced members mating with the cylindrical surfaces in the housing and an interconnecting portion mating with the valve seat, said plug being free to both unidirectionally rotate and reciprocate in the housing respectively about a concentric common axis of the cylindrical surfaces;
• an actuator axially interconnected with the plug for axially reciprocating the plug between seated and unseated positions;
• and
• a cam and cam follower cooperating with at least one of the cylindrical surfaces and a corresponding one of the cylindrical members for guiding said plug between the open and closed positions of the plug, said cam guiding the plug from rest in the open or closed position to open or close the flow path when the drive is actuated from rest at the seated position through the unseated position and back to the seated position, whereby axial movement of the drive causes simultaneous rotational and axial movement of the plug between open and closed positions.