Where three-way switching is required, a series of four port, three way directional valves are capable of switching high flows of up to 85 litre/min. Sterling Hydraulics (UK) has produced a new N04 series of four-port, three-way directional valves that can switch hydraulic pressure and flow from one component to another when operating manlifts, telescopic handlers, refuse trucks, crushers or other applications. The N04 pilot operated spool valves are capable of switching high flows of up to 85 litre/min and are important components in building hydraulic control systems. In a standard aluminium line body it can operate at up to 210 bar, and a zinc plated steel version is available for pressures up to 420 bar. The valves are available as normally open port 2 to port 1 (N04H4) or normally open port 2 to port 3 (N04G4). In either case the spool is shifted, at the valve setting, by pilot pressure against a return spring, with the spring chamber being vented to atmosphere where dual Shamban seals prevent hydraulic fluid leakage. Although the standard switching pressure is 10 bar, Sterling Hydraulics can supply the valves to suit customers’ requirements for other switching pressures.
