PURPOSE: To provide a valve of excellent reliability capable of operating without seepage by opening a poppet valve provided on a piston capable of seating on a valve seat by an actuator driven by line pressure, and hence driving the piston by the supplied in-line fluid pressure.

CONSTITUTION: A piston 4 is fitted into the chamber 3 of a valve main body 2 having an angularly bent flow passage, and by seating the bevel end part 5 of the front part of the piston 4 on a valve seat 7, communication between an inlet 8 and an outlet 9 is intercepted. By in-line fluid pressure fed in the rear chamber of the chamber 3 divided with the piston 4 when the hole 10 in the piston 4 is communicated by a poppet valve 23, the piston 4 is moved to close the valve. For controlling opening/closing of the poppet valve 23, an actuator 12 constituted by fitting a piston 14 in a cylinder 15 is provided, and the piston 14 is combined with the poppet valve 23 through a valve stem 20.