The Maxitrol RV47CL-1/2 Poppet Gas Regulator with Limiter is a precision control device for natural gas and propane systems in HVAC equipment such as furnaces and boilers. It maintains consistent downstream pressure (4" WC for NG, 10" WC for LP) by adjusting gas flow in response to demand, ensuring stable combustion and optimal performance. https://www.partshnc.com/gas-regulator-1-2-npt-for-fulton-boiler-part-rv47cl-1-2