High-performance proportional pressure-reducing valves from Sterling Hydraulics, Schaumburg, Ill., are suitable for mobile-equipment applications. The cartridge valves can be used for pilot control of large valves and control of variable displacement pumps and motors. The twoposition, three-way valves operate on barometric pressure feedback. Pressure to be controlled is applied to the face of the valve spool, which opposes the solenoid magnetic force. There is a proportional relationship between magnetic current and pressure to be controlled.

The valves are available for standard low-wattage "S" coils, (14 W) or high-wattage "P" coils (19 W). The pressure amperage displays low hysteresis, and can be fit for detented or nondetented manual override.