Fairchild PAX1 Linear Electric Actuator

The Fairchild PAX1 linear electric actuator puts remote, motorized setpoint control on spring-return pneumatic pressure regulators – no coupling required. Its rotating output rod drives against or with the regulator range spring, and the actuator locks in place on loss of power or signal to hold the last position. Designed for remote, explosionproof locations, the PAX1 is a natural fit for natural gas distribution and pipeline sites, including solar-powered stations that isolate power between moves.

Universal supply circuitry accepts 12-24 VDC or 110-240 VAC power. Open-loop control uses two optically isolated up/down switch inputs, while intermediate positioning is available through an isolated 4-20 mA analogue input or Modbus RTU over a two-wire RS-485 network direct to a PLC or DCS. Commissioning happens at the integral UP, DOWN, and SET push buttons in the top enclosure, and an 8 mm hex key provides manual override during power loss. Two adjustable SPDT limit relays are magnetically latched, so switch state survives with power disconnected.

Paired with Fairchild regulators, the PAX1 builds motorised regulator assemblies spanning vacuum service through 3,000 psig output – Models 16, 11, 4100A, 10, 81, HPD, and HPP mount directly, and adapter kits fit the Fisher Y600A and 161EBM and Mooney 20H/20L pilot regulators, plus a universal mounting kit for everything else. A non-rotating PAXL variant automates small valves and pumps with push-and-pull action; contact us to quote either configuration.