ACHEM ALSD series top valve controller which was developed and made by AFL Group is an optimizing solution for on/off valve control and position sensing in the process industries. Armed with low watt miniature pilot coil, spool valve, position sensors, and bus communication cards, the ALSD series top valve controller help plants, platforms and pipelines improve productivity and increase safety in the harshest environments and toughest applications.

Based on the standard design of Namur and ISO5211, the ALSD series top valve controller can be mounted on any rotary pneumatic actuators. As for the position sensing of the valve, the mechanical switch, proximity sensor, magnet sensor, ASi sensor and DeviceNet sensor are all available in ALSD series top valve controller. As for the on./off valve control, ALSD series top valve controller is suitable for use of 3/2 NC or 5/2 functions to control double-acting and single-acting pneumatic actuators and also is suitable for pilot operated with single/dual (mono/bi-stable) coils.