DUAL CIRCUIT BRAKE VALVE

摘要

A dual circuit brake valve includes a plunger assembly carrying the primary valve seat, and the primary valve plunger within the primary piston. A pair of axially-spaced, circumferentially extending bearing members extend from the primary piston slidably engaging larger and smaller diameter portions of the bore of the housing to thereby guide the primary piston independently of other components within the housing. The secondary set of valve actuating members is actuated by a relay piston which is similarly guided in larger and smaller diameters of the bore independently of other components within the valve housing. The primary piston defines a pressure effective area due to the difference in the larger and smaller portions, so that inlet port pressure acting on the effective area yieldably urges the plunger toward the brake released position.