Schneider Electric 9013FHG42J59 Pressure Switch

Schneider Electric's Square D Pumptrol 9013FHG42J59 is a 135–175 psi, single-port pressure switch designed to regulate air compressor operation. This fixed-differential, DPST switch opens and closes at about 135 psi and 175 psi, delivering a reliable on/off cycle for pump motors while maintaining pressure within the 135–175 psi window. It features a 1/4-inch FNPT threaded port for straightforward installation and wiring, and many listings note an integrated unloader valve to vent air when the switch trips, aiding startup and cycling. The unit is designed for control circuits up to 575 VAC and is offered in NEMA-rated enclosures (1 and 3R), making it suitable for indoor and light-industrial environments.