Key Benefits for Professionals: Universal Compatibility: Fits high-volume Williams series such as the 1403821

Key Benefits Optimized Fan Cycling: Precisely maintains head pressure by cycling condenser fans at 170/250 PSIG setpoints

If your furnace blower runs continuously while the burners stay off

ensuring the safe and efficient discharge of combustion gases from the heat exchanger to the venting system

provided the regulator body is rated for the fuel type

TB Woods 4J-3/4 Coupler Flange Key Benefits for Professionals: UniversalThe TB Woods 4J 3 4 Coupler Flange is a Type J Sure Flex Plus power transmission component engineered for heavy duty industrial and HVAC applications. Manufactured from high strength sintered carbon steel using a powdered metal process, this Size 4 flange provides exceptional dimensional accuracy and uniform material properties. It features a precision 3 4" bore with a standard 3 16" x 3 32" keyseat and a primary setscrew positioned over the keyway