Balanced supply-exhaust valve

Claim 1

A VALVE COMPRISING A CASING HAVING PRESSURE INLET MEANS, PRESSURE DELIVERY OUTLET MEANS AND PRESSURE VENTING MEANS, VALVE MEANS IN SAID CASING, SAID VALVE MEANS INCLUDING A RECIPROCAL PLUNGER HAVING AN AXIAL PRESSURE FLOW BORE THERETHROUGH AND LIKE AREA END PORTIONS SUBJECTED TO BALANCE PRESSURE ENDWISE OF SAID BORE, SAID RECIPROCAL PLUNGER BEING OPERATIVE IN A FIRST POSITION TO RECEIVE PRESSURE THROUGH THE INLET MEANS AND DELIVER IT TO THE OUTLET MEANS WHILE CLOSING OFF THE VENTING MEANS AND BEING OPERATIVE IN A SECOND POSITION TO CLOSE OFF PRESSURE COMMUNICATION BETWEEN THE INLET MEANS AND THE OUTLET MEANS WHILE OPENING COMMUNICATION BETWEEN THE OUTLET MEANS AND THE VENTING MEANS, SAID PLUNGER HAVING PASSAGEWAYS FOR RECEIVING PRESSURE THROUGH THE INLET MEANS AND DELIVER IT TO THE OUTLET MEANS IN THE FIRST POSITION OF SAID PLUNGER, SEAT MEANS NORMALLY CLOSING COMMUNICATION BETWEEN THE OUTLET MEANS AND THE VENTING MEANS IN THE FIRST POSITION OF SAID PLUNGER, MEANS NORMALLY BIASING SAID SEAT MEANS TO THE NORMAL POSITION THEREOF, AND MEANS MOVABLE WITH THE PLUNGER TO ENGAGE AND DISPLACE THE MEANS NORMALLY BIASING THE SEAT MEANS TO OPEN COMMUNICATION BETWEEN THE VENTING MEANS AND THE OUTLET MEANS AND CLOSING OFF COMMUNICATION THROUGH THE PLUNGER BETWEEN SAID INLET AND OUTLET MEANS.