Rotary valves

Claim 1

A BALL VALVE COMPRISING IN COMBINATION: (A) STRUCTURE INCLUDING FIRST AND SECOND DETACHABLE SECTIONS FORMING A VALVE BODY HOUSING; (B) SAID VALVE BODY HOUSING HAVING WALLS DEFINING A FLUID CHAMBER; (C) SAID CHAMBER HAVING AN INLET PORT AND AN OUTLET PORT SPACED FROM SAID INLET PORT; (D) A FIRST, CONTINUOUS, ANNULAR SEAL ELEMENT CIRCUMSCRIBING ONE OF SAID PORTS AND FORMING A VALVE SEAT; (E) SAID STRUCTURE INCLUDING AN ANNULAR MEMBER CARRIED BY THE FIRST SECTION TO FORM A CONTINUATION OF SAID ONE PORT, SAID VALVE SEAT BEING CARRIED BY THE ANNULAR MEMBER SO THAT SAID SEAT CAN BE REPLACED BY DISCONNECTING THE SECTIONS AND THE ANNULAR MEMBER; (F) A ROTATABLY MOUNTED VALVE BALL ASSEMBLY; (G) SAID ASSEMBLY INCLUDING A BALL HAVING A THROUGH PASSAGE AND BEING ROTATABLE IN SAID FLUID CHAMBER BETWEEN A FIRST POSITION IN WHICH SAID PASSAGE ESTABLISHES FLUID COMMUNICATION BETWEEN SAID INLET AND OUTLET PORTS AND A SECOND POSITION IN WHICH THE ENDS OF SAID PASSAGE ARE SPACED FROM SAID PORTS; (H) SAID ASSEMBLY INCLUDIING A RING OF POLYTETRAFLUOROETHYLENE DEFINING A SECOND CONTINUOUS SEAL; (I) SAID BALL INCLUDING A DETACHABLE PORTION NORMALLY HOLDING SAID RING IN POSITION SO THAT THE RING CAN BE REPLACED WITHOUT COMPLETELY REMOVING THE BALL FROM THE CHAMBER; (J) SAID SECOND SEAL BEING LOCATED TO MATE WITH SAID VALVE SEAT AT AN ANNULAR SEALING INTERFACE CIRCUMSCRIBING SAID ONE PORT WHEN SAID BALL IS IN SAID SECOND POSITION TO PREVENT FLUID FLOW BETWEEN SAID PORTS; (K) SAID PORTION DEFINING SAID SECOND SEAL AND ALL OTHER SURFACES OF SAID BALL BEING SPACED FROM THE WALLS OF SAID FLUID CHAMBER IN ALL POSITIONS OF SAID BALLS; AND (L) SAID FIRST SEAL BEING FORMED OF RUBBER.