Actuators & Control

How a solenoid valve works, what NC/NO and 2/2, 3/2, 5/2 mean, 24 V or 230 V coils, direct-acting or pilot-operated, and when to choose a solenoid valve versus a pneumatically actuated ball valve.

What people mean by electric or motorised valve, and how to size the actuator: 30–800 Nm torque, 24 V DC / 230 V / 400 V supply, IP67, on-off vs 4–20 mA modulating control, fail-safe and ISO 5211.

How a pneumatic valve works and how to choose between double acting and spring return actuators: ISO 5211 mounting, 2–8 bar air, fail-safe position, torque margin, NAMUR solenoids and limit switches.

An actuated valve is only as good as the accessories around it. Practical field rules for limit switch boxes, 4-20 mA positioners, 3/2 and 5/2 solenoid valves, air preparation sets, IP ratings and ATEX.

How ISO 5211 flange codes and square drive sizes work, what the NAMUR VDI/VDE 3845 interface standardises, when adapter kits are unavoidable, and how misalignment breaks valve stems.

Pneumatic or electric actuator? A field-focused comparison covering fail-safe behaviour, cycle life, speed, infrastructure cost and ambient conditions.

Get the torque calculation right and eliminate valves that fail to open or close. A field guide to safety factors, air supply pressure, ISO 5211 mounting, fail-safe action and accessories.