Chicago Safety Products HLGP-A-M1 Pressure Switch

The HLGP-A-M1 is a dual gas-pressure switch from Antunes Controls (Chicago Safety Products) designed for combustion-safety interlocks in gas-fired equipment. It combines a high-pressure and a low-pressure switch with a manual reset lever and a snap-action SPDT mechanism, enabling reliable changeover signaling as pressures move out of the prescribed ranges. The high-gas side covers 2–16 in. water column (in wc) and the low-gas side covers 1–6 in. wc, providing two independently adjustable thresholds in a single compact unit. The device uses standard gas-train fittings: a 3/8" NPT high-pressure inlet, a 1/8" NPT low-pressure inlet, and a 1/8" NPT vent, with a front gas-vent and side vents arranged for straightforward installation in typical burner assemblies. Its physical footprint places the front face at about 4 1/4" wide, with an overall length of approximately 5 3/8" to fit common mounting patterns. Intended for industrial combustion applications, HLGP-A-M1 serves as a safety interlock that signals a safety-control system when either the high or low gas pressure diverges from the setpoints, helping prevent unsafe burner operation. The HLGP-A family is frequently cited in cross-reference guides and replacement parts catalogs for Chicago Safety/Antunes gas-pressure switches, underscoring its role in standard gas-train configurations.