Convertible valve

Claim 1

A VALVE OF THE CLASS DESCRIBED COMPRISING: A VALVE BODY HAVING A PARTITION PROVIDED WITH A SMOOTH; CIRCULAR OPENING THERETHROUGH AND DIVIDING SAID BODY INTO AN INLET CHAMBER AND AN OUTLET CHAMBER PROVIDED, RESPECTIVELY, WITH ALINED AND SCREW THREADED OPENINGS IN ALINEMENT WITH SAID PARTITION OPENING; A REPALACEABLE SEAT ELEMENT HAVING A PLUG-FORMING PORTION SCREW THREADED INTO SAID OUTLET CHAMBER OPENING AND PROVIDED WITH A SMOOTH, CYLINDRICAL SHANK SLIDABLY FITTING INTO SAID PARTITION OPENING AND HAVING AN ANNULAR FLANGE; AND SHANK HAVING A PORT PLACING SAID CHAMBERS IN COMMUNICATION WITH EACH OTHER THROUGH SAID PARTITION OPENING AND BEING PROVIDED WITH A VALVE SEAT BOUNDING SAID PORT AND FACING SAID INLET CHAMBER; A YIELDABLE SEALING RING SEATING AGAINST SAID FLANGE IN FLUID-TIGHT ENGAGEMENT WITH SAID PARTITION WHEN SAID SEAT ELEMENT IS SCREWED TIGHTLY INTO SAID OUTLET CHAMBER OPENING AND SAID SHANK MOVES FREELY IN SAID PARTITION OPENING; A CYLINDRICAL CLOSURE ELEMENT HAVING AN INTERMEDIATE EXTERNALLY SCREW THREADED PORTION SCREWED INTO SAID INLET CHAMBER OPENING TO ENGAGE OR DISENGAGE SAID VALVE SEAT ACCORDING AS THE CLOSURE ELEMENT IS ROTATED IN ONE DIRECTEION OR THE OTHER; SAID CLOSURE ELEMENT HAVING AN ANNULAR STOP FLANGE; A CUPSHAPED RETAINER AND STOP SCREW THREADED ON SAID BODY AND HAVING A CENTRAL OPENING FREELY RECEIVING THE OUTER END OF SAID CLOSURE ELEMENT; A CUP-SHAPED PACKING GLAND SEATING IN THE SAID RETAINER AND HAVING PORTIONS URGED BY THE RETAINER INTO FLUID-SEALING ENGAGEMENT WITH THE PERIPHERIES OF THE UNTHREADED PORTION AND STOP FLANGE OF SAID CLOSURE ELEMENT SO AS TO PREVENT LEAKAGE OF FLUID FROM THE INLET CHAMBER PAST THE CLOSURE ELEMENT IN ANY AND ALL POSITIONS OF THE LATTER; AND AN OPERATING MEMBER SECURED TO SAID CLOSURE ELEMENT.