DG3S4042A740

The DG3S4042A740 valve belongs to the Directional Control Valves series manufactured by Vickers for hydraulic automation systems that require directional control of pressurized fluid. It is pilot operated, so a separate control pressure shifts the spool without large electrical solenoids. The unit is designed as a two-stage assembly, enabling the small pilot stage to move the main spool for consistent performance under load. External pilot supply allows the control oil to be taken from an independent source, and an external pilot drain returns it directly to tank to prevent back-pressure on the pilot circuit. The interface follows ISO 4401-07, providing a common port pattern for quick replacement among similarly sized valves. Subplate or manifold mounting lets the valve sit flush on a hydraulic base plate, reducing piping. A maximum flow rating of 60 GPM accommodates medium-capacity circuits without excessive pressure drop. The permitted operating temperature reaches 70 °C, which ensures reliable service while protecting internal components.

Petroleum oils are the approved working fluids, and Buna-N seals are fitted to resist swelling and leakage when those oils are used. System cleanliness must be maintained at ISO 4406 code 19/17/14 to minimize spool wear and sticking. The valve employs spool type 2, defining the flow paths that open or close during actuation. Stroke adjustment is provided only at the port A end, allowing fine tuning of spool travel for one flow direction. A spring offset from end to end returns the spool to its normal position when pilot pressure is removed. There is no indicator light, so electrical feedback must be provided externally if required. The design also omits a manual override, meaning the spool cannot be shifted by hand during service. These features make the DG3S4042A740 suited for installations where remote hydraulic control and compact manifold layouts are preferred.