Coils

Air solenoid valve coils are used for electrical actuation of solenoid valves in pneumatic automation circuits. When energized, the coil generates a magnetic field in the valve body and shifts the armature or spool, enabling port switching in 3/2, 5/2, or 5/3 valve configurations, depending on the valve design. Coil selection should be based on supply voltage, AC or DC type, power consumption, connector format, thermal load, duty cycle, and compatibility with the valve series.

This category includes Hafner MA16, MA22, and MA30 coils for pneumatic solenoid valves, together with ST16, ST22, ST30, and ST3-10 plug connectors. MA16 coils are intended for 16 mm MD-series valves and are available in 6, 12, and 24 V DC versions rated at 1.8 W, as well as 24, 110, and 230 V AC versions rated at 3 VA, with Form C connection to DIN EN 175301-803 or cable lead. MA22 coils for the MH-series are supplied in Form B, with typical ratings of 3 W DC or 5 VA AC. MA30 coils use Form A connectors in accordance with DIN 43650-A / DIN EN 175301-803.

For hazardous areas, ATEX / IECEx Hafner coils are available, including MA22 EEx m II T4, MA30 Ex ia IIC T6, MA52 EEx e mb IIC T6, MA36 EEx dm IIC T5, and MH52 Ex d IIC T6. These versions must be selected according to hazardous area zone, gas group, temperature class, wiring method, and whether the installation requires intrinsic safety or flameproof protection.

Coil plugs are available in Form C, Form B, and Form A patterns, with voltage ratings up to 250 V and maximum current ratings of 6, 10, or 16 A depending on type. Versions with LED indication and varistor suppression are used for energization status indication and transient overvoltage protection.

During maintenance, checks should include coil resistance, voltage present at the connector, cable entry sealing, thermal stress, correct grounding, and coil-to-valve compatibility. Coil failure, incorrect voltage, or moisture ingress at the plug can result in failure to shift, overheating, or unstable pneumatic circuit operation.