The ASCO Series 551 is a compact, high-performance NAMUR-mount spool valve designed for reliable control of pneumatic actuators in industrial environments. It is available in 3/2 NC and 5/2 functions and can be adapted between the two by changing the supplied interface plate. The valve features a pilot-operated, mono- or bi-stable design, with aluminium or brass construction depending on the model. It offers robust environmental protection thanks to connectable exhaust ports, allowing the prevention ingress of dust, moisture, and contaminants-particularly valuable in food, pharmaceutical, and clean-room applications

