The ASCO Series 551, 552, 553 pilot operated solenoid valves with NAMUR interface are reliable and durable control solutions for a variety of industrial and commercial applications. These valves are available in a range of configurations and are certified for use up to SIL 4, making them suitable for use in safety-critical systems. They have TÜV certified IEC 61508 Functional Safety data and offer environmental protection against the ingress of liquids, dust, and other foreign matter. This makes them particularly well-suited for use in sensitive areas such as clean rooms and in the pharmaceutical and food processing sectors. The ASCO pilot operated valves are able to control double-acting and single-acting actuators and can be adapted for 3/2 NC or 5/2 function. They also feature a NAMUR interface that helps to prevent the actuator from breathing in air from the environment, which can be a potential source of failure. Overall, the ASCO Series 551, 552, 553 pilot operated solenoid valves are reliable and effective control solutions for a range of applications.