Relief valve

Claim 1

A RELIEF VALVE FOR USE IN A FLUID SYSTEM COMPRISING, A BODY HAVING A CYLINDRICAL-LIKE STEM PROJECTING OUTWARDLY THEREFROM, A HOLLOW CYLINDRICAL MAIN POPPET MEMBER MOUNTED FOR AXIAL MOVEMENT ON SAID STEM, SAID STEM INCLUDING A LARGER CYLINDRICAL PORTION ADJACENT THE JUNCTURE OF THE STEM WITH THE BODY AND A SMALLER CYLINDRICAL PORTION ADJACENT THE DISTAL END OF SAID STEM, SPACED SEALING MEANS COACTING BETWEEN SAID LARGER STEM PORTION AND THE INTERIOR OF SAID POPPET MEMBER AND BETWEEN THE LATTER AND SAID SMALLER STEM PORTION AND SEALING THE INTERIOR OF SAID POPPET MEMBER AGAINST EGRESS OF FLUID THEREFROM, A HOLLOW CYLINDRICAL-LIKE VALVE SEAT ANCHORED TO THE DISTAL END OF SAID STEM, SAID VALVE SEAT COMPRISING, AN END WALL ANCHORED TO SAID STEM AND A GENERALLY AXIALLY EXTENDING SIDE WALL CIRCUMFERENTIALLY ENCOMPASSING SAID STEM, SAID VALVE SEAT BEING ADAPTED FOR ENGAGEMENT BY SAID POPPET MEMBER, SAID END WALL HAVING A PLURALITY OF APERTURES THERETHROUGH FOR EXPOSING SAID POPPET MEMBER TO SYSTEM PRESSURE, RESILIENT MEANS DISPOSED INTERIORLY OF SAID POPPET MEMBER AND URGING THE LATTER INTO SEALING ENGAGEMENT WITH SAID SEAT, THE SEALING AREA AT SAID SEAT BEING LESS THAN THE SEALING AREA AT SAID LARGER STEM PORTION FOR PROVIDING A FLUID UNBALANCING FORCE TO SUPPLEMENT SAID RESILIENT MEANS, SAID VALVE SEAT HAVING A CIRCUMFERENTIAL SKIRT ENCOMPASSING A PORTION OF THE AXIALLY EXTENDING EXTERIOR OF SAID POPPET MEMBER AND PROVIDING A THROTTLING SECTION, FLUID TRANSMITTING PASSAGEWAY MEANS EXTENDING AXIALLY THROUGH SAID STEM FROM SAID DISTAL END, APERTURE MEANS COMMUNICATING SAID PASSAGEWAY MEANS WITH THE INTERIOR OF SAID POPPET MEMBER, METERING MEANS DISPOSED IN SAID PASSAGEWAY MEANS FOR RESTRICTING THE FLOW OF PRESSURIZED FLUID INTO THE INTERIOR OF SAID POPPET MEMBER, SAID VALVE HAVING A CHAMBER THEREIN SPACED FROM SAID METERING MEANS AND SAID APERTURE MEANS, SAID CHAMBER HAVING AN EXIT PORT, A PILOT VALVE SEAT COMMUNICATING SAID PASSAGEWAY MEANS WITH SAID CHAMBER, A PILOT VALVE MEMBER DISPOSED IN SAID CHAMBER, AND INCLUDING RESILIENT MEANS URGING SAID PILOT VALVE MEMBER INTO ENGAGEMENT WITH SAID PILOT VALVE SEAT, SAID PILOT VALVE MEMBER BEING ADAPTED TO OPEN AT A PREDETERMINED FLUID PRESSURE LOWER THAN A PREDETERMINED SYSTEM PRESSURE AT WHICH SAID MAIN POPPET IS ADAPTED TO OPEN, WHEREBY SAID MAIN POPPET MEMBER IS PLACED IN A CONDITION OF FLOATING EQUILIBRIUM AT SAID PREDETERMINED SYSTEM PRESSURE.