The Garland 4522421 Range Pressure Regulator Natural Gas 1\" 4-8\" WC R600 regulates the pressure of the incoming natural gas to ensure a constant flow level of the required burner system. It works by regulating the internal processes that react to the changes in the gas supply so that the appliance is provided with the correct range of pressure to operate correctly. This regulator is mounted on the supply line of gas usually it is mounted close to the main inlet connection to control the distribution before it reaches the burner parts.