Removable valve head and seat unit

Claim 1

IN COMBINATION: A FLUID SUPPLY MEMBER HAVING AN INTERNAL SHOULDER AND A PAIR OF SPACED APART PARALLEL BORES, A VALVE ASSEMBLY RELEASABLY SEATED ON THE SHOULDER, THE ASSEMBLY COMPRISING: A DUCT PIECE RESTING ON THE SHOULDER, AN INLET COMMUNICATING WITH ONE OF SAID PARALLEL BORES AND AN OUTLET, A VALVE CLOSURE GUIDABLY ASSOCIATED WITH SAID DUCT PIECE FOR MOVEMENT BETWEEN AN OPEN AND A CLOSED POSITION RELATIVE TO SAID FLUID OUTLET OF SAID DUCT PIECE, AND MANUALLY OPERABLE SPRING MEANS YIELDABLY URGING SAID VALVE CLOSURE TOWARD SAID CLOSED POSITION; SAID DUCT PIECE COMPRISING A SUBSTANTIALLY RIGID L-SHAPED MEMBER HAVING A PAIR OF PERPENDICULARLY RELATED LEGS WITH AN INTERNAL BORE EXTENDING AT LEAST PARTIALLY THROUGH EACH SAID LEG, ONE END OF THE BORE IN ONE LEG DEFINING AND FLUID INLET, AND A SEAT INTEGRAL WITH THE OTHER ONE OF SAID LEGS DEFINING SAID FLUID OUTLET; AND WHEREIN SAID FLUID SUPPLY MEMBER INCLUDES A SUMP INTERMEDIATE SAID PARALLEL BORES OF SUBSTANTIALLY LARGER DIAMETER AND GREATER DEPTH THAN SAID SEAT, AND SAID BEING RECEIVED WITHIN SAID SUMP, THE SPACE BETWEEN SAID SEAT AND SAID SUMP PROVIDING COMMUNICATION BETWEEN THE OTHER ONE OF SAID PARALLEL BORES AND SAID OUTLET.