This part number typically refers to the Pyrolite chamber itself

providing immediate gas flow once the solenoid is energized

The Alco X-11873-B5B cage is built to maintain system stability under varying load conditions

or a "tripping" high-limit switch

Durable Construction: Engineered to withstand the heat and vibration of furnace draft inducer housings

Carrier EA02DZ517 Expansion Valve 318172-701 This part number typically refersThe Carrier EA02DZ517 Thermal Expansion Valve is a critical metering device engineered for precise refrigerant control in residential and commercial HVAC systems. This OEM Carrier TXV is the direct replacement for the obsolete EA02DZ515, ensuring a seamless drop in fit for older units without the need for extensive piping modifications. Designed specifically for R 22 refrigerant systems, it utilizes a bi metal composition and a sweat braze connection