Abstract: A method for odorizing natural gas in the pipeline utilizes bypass piping in conjunction with a liquid odorant storage tank. The bypass line causes a precisely known volume of bypass gas, saturated with odorant, to enter the gas line at regular intervals determined by gas flow through the line. Natural gas, having a known pressure higher than the pipeline pressure, is provided to the bypass line, and controlled by a control valve. The flow characteristics of the control valve are known in advance, so that opening the valve for a known time period allows a known quantity of bypass gas to flow through the valve. A controller monitors the gas line, and each time a pre-determined quantity of gas flows through the line, the control valve is opened for the calculated time. The bypass line is connected from the control valve to the odorant tank, and from the odorant tank to the gas line.