The 3/4" NPT thermowell must be purchased separately to facilitate installation into the process piping

Although it is factory set at 5 psi

providing the critical pressure differential sensing required to engage the control board and burner tray

providing flexibility for non-grounded control circuits

meaning it does not allow pressure equalization during the off-cycle

Robertshaw 700-503 Gas Valve Els PW 29614 The 3/4" NPT thermowell mustThe Robertshaw 700 503 Gas Valve is a millivolt combination gas control designed for heavy duty HVACR applications, including high capacity 1" pipe systems up to 720,000 BTU. This wall thermostat actuated valve features a 1 2" FPT inlet and a 3 4" FPT straight thru outlet, with additional 1 2" FPT side taps provided for installation flexibility in tight furnace or pool heater cabinets. As a non regulated (7000BMV) model, it is engineered for systems