GRADUATED RELEASE VALVE DEVICE

PROBLEM TO BE SOLVED: To provide a graduated release valve device reducing pressure within a brake cylinder in stages in response to every increase in internal pressure of a brake pipe of a train. SOLUTION: A first end 114 and a second end of a valve element 110 are connected to the brake pipe via an inlet check valve 140 and an outlet check valve 160, respectively, and communicated with each other through a passage 120 having a restriction 123. The pressure rise in the brake pipe causes a pressure rise at the first end through the inlet check valve, so that the valve element moves to an open position, and the brake cylinder and an exhaust passage having a restriction 182 are communicated with each other. As differential pressure between both the ends of the valve element via the restriction 123 reduces, the valve element is returned to a closed position by a spring 113. The presence of the outlet check valve does not cause internal pressure of the valve element to exceed the pressure in the brake pipe.