Abstract: A non-flowing pilot operated relief valve system having modulating action includes a relief valve and a pilot valve. The pilot valve includes a body forming a channel, an inlet port, a control port, and a vent port. A portion of the channel forms an inlet chamber in communication with the inlet port. A piston is axially movable within the channel and has a vent-valve seat communicating the control port and the vent port. A spool extends through the sleeve and is substantially coaxial with the piston. The spool is axially movable within the channel in response to fluid pressure within the inlet chamber. The spool has an inlet-valve seal member closable on the inlet-valve seat and a vent-valve seal member closable on the vent-valve seat. The spool is adapted such that the inlet-valve seal member is seated on the inlet-valve seat when the a vent-valve seal member is unseated from the vent-valve seat.