This odorizing system is based on adsorption.
The system does not need injection pumps but uses the pressure of the gas line. A by-pass flow from the main line withdrawn by an adjustable butter fly valve or orifice, the pressure of the gas line is used as the motive force. The system is normally used in combination with the lapping system ,By-pass odorizer is used especially for smell or low capacity stations ,where they are very cost effective and economic.