Valve subjected to exterior moisture,as an underground gas distribution valve

Claim 1

A VALVE SUBJECTED TO EXTERIOR MOISTURE, AS AN UNDERGROUND GAS DISTRIBUTION VALVE, COMPRISING A CASING HAVING INLET AND OUTLET CONNECTIONS, A TURABLE VALVE STEM PROJECTING FROM THE CASING, A VALVE ELEMENT IN THE CASING, CONNECTIONS BETWEEN THE STEM AND THE VALVE ELEMENT MOVING THE VALVE ELEMENT BETWEEN OPEN AND CLOSED POSITIONS UPON TURNING OF THE STEM, THE CASING AND STEM BEING SHAPED TO PROVIDE AN ANNULAR PACKING RECEIVING CHAMBER ABOUT THE STEM INWARDLY OF THE PORTION OF THE CASING WHERE THE STEM PROJECTS FROM THE CASING, PACKING IN THE CHAMBER A THRUST COLLAR CONFINING SAID PACKING BETWEEN THE CASING AND THE STEM, AN ADAPTER RING IN THE CHAMBER OUTWARDLY OF THE PACKING, TWO PARALLEL SPACED ANNULAR INNER GROOVES IN THE ADAPTER RING IN COMMUNICATION WITH THE STEM, O RINGS POSITIONED IN THE RESPECTIVE SPACED ANNULAR INNER GROOVES OF THE ADAPTER RING AND ENGAGING THE VALVE STEM, TWO PARALLEL SPACED ANNULAR OUTER GROOVES IN THE ADAPTER RING IN COMMUNICATION WITH THE CASING AND O RINGS POSITIONED IN THE RESPECTIVE SPACED ANNULAR OUTER GROOVES OF THE ADAPTER RING AND ENGAGING THE CASING, THE O RINGS POSITIONED IN THE INNER AND OUTER GROOVES REMOTE FROM THE PACKING AND ADJACENT SAID THRUST COLLAR SERVING TO COLLECT SOLID PARTICLES ENTERING THE RECEIVING CHAMBER BETWEEN SAID THRUST COLLAR, SAID STEM AND SAID CASING, WHICH SOLID PARTICLES PACK AROUND SAID LAST NAMED O RINGS, PREVENTING PASSAGE OF SOLID PARTICLES TO THE O RINGS IN THE INNER AND OUTER GROOVES ADJACENT TO THE PACKING AND ENABLING SAID LAST MENTIONED O RINGS TO BE FULLY EFFECTIVE IN INHIBITING LEAKAGE OF FLUID THEREPAST.