Patent ID: 7975715

Claim:
A valve for use in a truck-trailer system having a source of air under pressure, a reservoir, at least one spring brake unit and a brake service line, the valve comprising: a body having a supply passage in communication with the associated source of air under pressure; a pressure protection valve portion that includes a first valve member and is operably disposed within a first chamber of the body, the first chamber having an inlet for communication with the supply passage and an outlet for communication with the reservoir, the pressure protection valve portion configured to selectively block the flow of pressurized air from the supply passage through the first chamber to the reservoir until a predetermined pressure is reached; a spring brake actuation valve portion operably disposed within a second chamber of the body, the second chamber having an inlet for communicating with the supply passage, at least one delivery outlet passage in selective communication with the at least one spring brake unit and an exhaust outlet in selective communication with the at least one spring brake unit, the spring brake actuation valve portion controlling pressurized air flow toward the at least one spring brake unit and the exhaust outlet; and an anti-compounding valve portion operably disposed within a third chamber of the body for preventing simultaneous application of the at least one spring brake unit and at least one service brake unit, the third chamber having a first inlet in communication with the supply passage, a second inlet in communication with the brake service line and a first outlet in communication with the first chamber and a second outlet in communication with the second chamber, the anti-compounding valve portion preventing flow of pressurized air from the brake service line towards the spring brake actuation valve portion; wherein the anti-compounding valve portion includes a second valve member that includes an annular portion having a first surface in sealing engagement with a third chamber first valve seat and a second surface in sealing engagement with a third chamber second valve seat.