Gas valves are used to regulate natural gas or liquid propane in heating systems. Gas valves vary in capacity (cubic ft of gas), inlet/outlet size, and type (standing pilot, slow opening, and step opening).
Gas valves and controls must match the heating system's fuel type. Liquid propane and natural gas conversion kits are available if the valve must be converted to meet a system's requirements. After the system type is verified, the system's capacity must be determined. Whether a normally open or normally closed gas valve is selected depends on the expected usage frequency of the valve.