These two-stage valves limit system pressure by directing flow to tank or the opposite cylinder port (A-B/B-A cross port types) when system pressure reaches the valve setting. Pressure control may be obtained in “A”, “B”, “A” and “B”, or “P” port, and pilot flow may be internally or externally drained, depending on model type. Any pressure in the line to which these valves are drained is additive to the valve pressure setting.