Unibody master-slave discharge valve assembly for CO.sub.2 systems

A discharge valve assembly for a pressurized fluid containment system, said discharge valve assembly comprising:

• an elongate valve body having a first longitudinally extending bore defining a primary valve chamber adapted to be connected to a fluid pressure source, the bore being eccentrically disposed thereby providing a thickened wall portion to one side of said valve chamber;
• a discharge port traversing said thickened wall portion and communicating with said primary valve chamber;
• a second longitudinally extending bore defining a secondary valve chamber generally parallel to the primary chamber and communicating at one end with the primary valve chamber and at the other end with the discharge port;
• a primary valve member displaceable within the primary valve chamber from a closed position to an open position by fluid pressure acting on a first end of the valve member, and having a pressure equalization opening admitting a holding portion of the pressurized fluid to a second end of the valve member for normally holding the valve in the closed position;
• a slave valve member disposed within said secondary valve chamber, one end of said slave valve member being in communication with the holding portion and the other end venting to atmosphere;
• and
• an actuating piston displaceable within said secondary valve chamber, a first end of said piston being in communication with said discharge port and a second end being in communication with the atmosphere, wherein a predetermined pressure in said discharge port displaces said actuating piston to displace said slave valve member to an open position and allow the holding portion of the pressurized fluid on the second end of said primary valve member to vent to atmosphere thereby permitting the pressurized fluid acting on the first end to displace said first valve member to the open position and permit the pressurized fluid to flow through said discharge port.