Plug valve assembly and method of making

Claim 1

IN A PLUG VALVE ASSEMBLY HAVING A BODY FORMED WITH FLUID INLET AND OUTLET PASSAGES OPENING AT THEIR INNER ENDS INTO A VALVE PLUG CAVITY, MEANS PROVIDING AXIALLY SPACED APART VALVE PLUG SEATING SURFACES POSITIONED IN SAID CAVITY RESPECTIVELY IN SURROUNDING RELATION TO THE INNER ENDS OF SAID PASSAGES, A PORTED BALL TYPE PLUG STRUCTURE SUPPORTED ON SAID SEATING SURFACES WITHIN SAID CAVITY FOR ROTATION BETWEEN POSITIONS WHERE IT RESPECTIVELY BLOCKS AND PROVIDES FLUID COMMUNICATION BETWEEN SAID PASSAGES, AND SURFACE MEANS ON SAID PLUG STRUCTURE AND COACTING WITH SAID SEATING SURFACES TO PROVIDE ANNULAR SEALS AROUND THE INNER ENDS OF SAID PASSAGES WHEN SAID PLUG STRUCTURE IS ROTATED TO ITS BLOCKING POSITION, SAID PLUG STRUCTURE, SAID BODY, AND SAID MEANS PROVIDING SAID SEATING SURFACES DELIMITING AN INTERNAL SPACE, THE IMPROVEMENT COMPRISING A SOLID FILLER SUBSTANTIALLY ENTIRELY OCCUPYING SAID SPACE AND HAVING A RUNNING CLEARANCE WITH SAID PLUG STRUCTURE, SAID FILLER BEING FORMED FROM A MATERIAL WHICH IS DIFFERENT FROM THE MATERIAL FORMING THE MEANS PROVIDING SAID SEATING SURFACES.