this 2-way normally closed valve features a 1/2" ODF sweat inlet and a 5/8" ODM sweat outlet

This is a specific Bradford White replacement part

Robust Construction: Built to withstand the high temperatures and vibrations of HVAC compressor protection environments

ensuring precise flow regulation to the burner assembly

Its primary function is to prove the induced draft fan is moving sufficient air to vent combustion gases safely

Lennox 73K19 Limit Switch 320074-702 this 2-way normally closed valveThe Lennox 73K19 is a technical grade L160 30F Limit Switch engineered for critical temperature oversight in residential and commercial HVAC furnace units. This OEM disc style limit control features a normally closed (NC) circuit configuration and utilizes an automatic reset mechanism for system continuity. As a primary safety component, the switch is calibrated to open the electrical circuit when the sensed temperature reaches its high limit cutout