This gasket is the primary valve seal for Series 53

specifically crossing CS4AN02A24 and CS4AF02A18

ensuring safe and optimal gas regulator performance across natural gas or LP applications

and MC-4311 series

Armstrong Furnace R43127-001 Flame Sensor This gasket is the primaryThe Armstrong Furnace R43127 001 Flame Sensor is a critical OEM replacement part designed for precision flame rectification in residential heating systems. This furnace flame sensor acts as a primary safety component, communicating directly with the integrated furnace control board to confirm burner ignition. If the sensor fails to detect the required microamp signal within the ignition trial period, the system triggers a safety lockout to prevent the