A screw-in, cartridge style, direct acting, spool type, hydraulic pressure reducing and relieving valve with internal spring chamber drain. When the pressure at port (1) is below the valve setting, the valve allows the flow to pass bidirectionally from (1) to (2). When the pressure at port (1) exceeds the valve setting, the spool shifts to restrict the flow at port (2), relieving or reducing the pressure at port (1) depending on the flow direction. A further pressure increase in port (1) causes the spool to shift against the spring so that the flow is relieved to tank (3). The system is self-regulated and stable thanks to an appropriate negative feedback. The spring chamber is constantly drained to tank.