Abstract: A pilot operated relief valve is disclosed which includes a first control space operatively connected to the inlet fluid channel, and a second control space operatively connected to the outlet fluid channel. In one embodiment, each control space is connected to a relief outlet by means of an adjustable valve, whereby the valve is adapted to operate as a pressure relief valve in either flow direction. In another embodiment, one of the control spaces is connected to the opposite channel by means of a one-way check valve, so as to function as a makeup fluid supply valve upon the pressure in the opposite channel reaching a predetermined low level.

Abstract: A pilot operated relief valve is disclosed which includes a first control space operatively connected to the inlet fluid channel, and a second control space operatively connected to the outlet fluid channel. In one embodiment, each control space is connected to a relief outlet by means of an ajustable valve, whereby the valve is adapted to operate as a pressure relief valve in either flow direction. In another embodiment, one of the control spaces is connected to the opposite channel by means of a one-way check valve, so as to function as a makeup fluid supply valve upon the pressure in the opposite channel reaching a predetermined low level.