Rotary plug valve having adjustable seats

Claim 1

A PLUG VALVE COMPRISING A VALVE BODY HAVING A PLUG RECEIVING CHAMBER THEREIN, AN ACCESS OPENING IN A SIDE OF SAID BODY IN COMMUNICATION WITH SAID CHAMBER AND THROUGH WHICH THE HEREINBELOW SPECIFIED PLUG AND SEALING DEVICES MAY BE REMOVED, AND ALIGNED FLOW PASSAGES SUBSTANTIALLY PERPENDICULAR TO THE AXIS OF SAID OPENING AND TERMINATING AT THEIR INNER ENDS IN PORTS RESPECTIVELY IN TWO OPPOSITE WALLS OF SAID CHAMBER, WHICH WALLS INCLUDE SMOOTH, FLAT BEARING SURFACES RESPECTIVELY SURROUNDING SAID PORTS AND OPPOSITELY INCLINED RELATIVE TO A PLANE EXTENDING PERPENDICULAR TO THE AXIS OF SAID PASSAGES SO THAT SAID SURFACES DIVERGE FROM EACH OTHER TO PROVIDE A WEDGE-SHAPED PLUG-RECEIVING SOCKET WHICH EXPANDS TOWARD THE OPENING; A SPHERICAL PLUG HAVING A BORE THERETHROUGH, DISPOSED ROTATABLY IN SAID CHAMBER FOR MOVEMENT OF SAID BORE INTO AND OUT OF ALIGNMENT WITH SAID PASSAGES TO CONTROL FLUID FLOW THROUGH THE VALVE, AND HAVING MEANS ASSOCIATED THEREWITH ACCESSIBLE ON THE EXTERIOR OF THE VALVE FOR ROTATING THE PLUG; A PAIR OF SEALING DEVICES INTERPOSED RESPECTIVELY BETWEEN THE PLUG AND EACH OF SAID CHAMBER WALLS AND SLIDABLY ENGAGING SAID BEARING SURFACES SO AS TO BE MOVABLE GENERALLY TOWARD AND AWAY FROM SAID OPENING, EACH OF WHICH DEVICES COMPRISES A SEAT RING OF DEFORMABLE MATERIAL IN PRESSURE SEALING ENGAGEMENT WITH BOTH SAID PLUG AND AN OPPOSED SURFACE OF THE VALVE BODY AROUND A RESPECTIVE ONE OF SAID PORTS AND A RETAINER ELEMENT THEREFOR OF RIGID CONSTRUCTION HAVING AN OPENNING EXTENDING AXIALLY THERETHROUGH IN WHICH SAID RING IS DISPOSED REMOVABLY AND SUFFICIENTLY LOOSELY TO PERMIT AXIAL MOVEMENT OF THE RING RELATIVE TO THE RETAINER ELEMENT, THE DEFINING WALL OF WHICH OPENING EXTENDS COMPLETELY AROUND SAID RING AND IS OF SUFFICIENT AXIAL EXTENT TO ENCLOSE AT LEAST SUBSTANTIALLY THE WHOLE OF THE OUTER PERIPHERY OF THE RING; AND BONNET STRUCTURE SECURED IN CLOSING RELATION TO SAID ACCESS OPENING AND REMOVABLE TO PERMIT WITHDRAWAL OF SAID PLUG AND SEALING DEVICES THROUGH THE ACCESS OPENING; SAID PLUG BEING FREE TO MOVE RELATIVE TO SAID BONNET STRUCTURE AND THE VALVE BODY UNDER THE POSITIONING CONTROL OF SAID SEALING DEVICES; SAID BONNET STRUCTURE INCLUDING ADJUSTMENT MECHANISM OPERABLE TO EFFECT SELECTIVE CONTROL OF THE SEALING PRESSURE ON SAID SEAT RINGS, WHICH MECHANISM COMPRISES RIGID STRUCTURE, DISTINCT FROM SAID PLUG, DIRECTLY ENGAGEABLE WITH SAID RETAINER ELEMENTS AND OPERABLE INDEPENDENTLY OF THE PLUG TO FORCE SAID SEALING DEVICES, AND THEREBY THE PLUG, IN THE DIRECTION OF CONVERGENCE OF SAID BEARING SURFACES SO AS THEREBY TO WEDGE SAID SEAT RINGS AND PLUG BETWEEN SAID SURFACES AND IMPOSE SEALING PRESSURE ON THE SEAT RINGS, SAID ADJUSTMENT MECHANISM FURTHER COMPRISING A CONTROL ELEMENT DISTINCT FROM SAID PLUG AND ACCESSIBLE FOR ADJUSTMENT EXTERIORLY OF THE VALVE BODY, AND MEANS DISTINCT FROM THE PLUG AND INDEPENDENT THEREOF AFFORDING AN INFLEXIBLE CONNECTION BETWEEN SAID CONTROL ELEMENT AND SAID RIGID STRUCTURE FOR EFFECTING SAID OPERATION OF THE RIGID STRUCTURE IN RESPONSE TO ADJUSTMENT OF THE CONTROL ELEMENT.