CAMPBELL HL031000AV Pressure Switch Unloader Valve

The HL031000AV is a Campbell Hausfeld four‑port pressure switch with a 90‑degree unloader valve, designed for use as an OEM replacement on standard air compressors. It switches at 95 psi (cuts in) and 125 psi (cuts out), with a 1/4" compression unloader fitting for the check‑valve line at a 90° angle and an integrated unloader tube for rapid pressure relief when the motor stops. This unit is rated for 120 V AC at up to 20 A or 240 V AC at up to 12 A, and features an on/off lever for manual control. Suitable for Campbell Hausfeld 4‑port configurations, it’s commonly used as a direct replacement in DIY and light commercial compressors requiring a universal HL031000AV pressure switch.