Spherical valve seal piston detecting and locking arrangement

Claim 1

A spherical valve including a housing having a fluid inlet and a fluid outlet, and provided with an annular groove surrounding said fluid inlet; a rotor rotatably supported within said housing, said rotor having a fluid flow passage therein for selective alignment with the inlet and outlet of housing to permit fluid through the housing; a first seal element on the rotor; a second seal element movably carried by said housing within said annular groove and adapted to be selectively engaged with the first seal element on the rotor when the rotor is in a position wherein the fluid flow passage is not interconnecting the inlet and outlet of the housing, the engagement of said second seal element with said first seal element operating to block fluid flows, said second seal element being movably disposed within said annular groove and constructed and arranged to form a first fluid chamber on one side thereof, said first chamber when pressurized operating to move said second seal element out of sealing engagement with said first seal element, and a second fluid chamber on the opposite of said second seal element and operable when pressurized to effect movement of said second seal element into fluid sealing engagement with said first seal element; means for supplying fluid under pressure to said first and said second chambers selectively; a tubular locking member defining an axial bore movable into and out of positive engagement with said second seal element, said locking member when in engagement with said second seal element operating to positively lock said second seal element in sealing engagement with said first seal element; said locking member having an axial bore therethrough, said locking number having a pilot end portion and a threaded portion adjacent to and inwardly of the pilot end portion; a threaded bore in said valve housing in communication with said second fluid chamber, said bore having a cylindrical guide portion adjacent the inner axial end of the said bore; tool accepting means on the external end of said locking member to facilitate the manipulation of the said locking member into and out of locking engagement with said second seal element; and, fluid sealing means operable between the cylindrical guide surface of said bore and the pilot end of said locking member.