ASCO WT8551A001MS Spring Return Control Valve

ASCO WT8551A001MS is a direct-mount inline spool valve from ASCO’s Series 8551, a spring-return 3-way/2-position solenoid valve designed for compact pneumatic control up to 150 psi. This 1/4‑inch port device is configurable for 3/2 or 5/2 operation and uses NAMUR mounting for easy integration with compatible actuators. The 24 V DC coil variant WT8551A001MS draws about 6.9 W, with alternative coil options available for other voltages (e.g., 120/60 Hz or 110/50 Hz) to suit different power supplies. Its aluminum body with NBR seals provides a robust, lightweight construction, and a venting feature on the spring side helps prevent actuator corrosion in spring-return configurations. Key performance figures include a flow coefficient (Cv) of approximately 0.86 and an operating differential pressure range of 30–150 psi, with fluids operable from 5 to 140 °F for applicable coil configurations. This combination makes the WT8551A001MS well suited for automation lines requiring precise, rapid actuation of pneumatic cylinders or clamps, while the spring return ensures the valve reliably resets when power is removed.