July 2011, Vol. 238 No. 7

Features

The Fundamentals Of Pipeline Gas Chromatographs

Gas chromatographs (GCs) are installed all over natural gas pipeline networks, providing an analysis of the flowing gas and calculating the physical properties used for the flow calculations and for custody transfer. However, a clear understanding of just how the GC works and the considerations that need to be made for the installation and operation of the GC are often lacking in the industry. This article discusses the major components of the GC and provides an understanding of the theory and practice of gas chromatography in the pipeline industry. Natural gas in a pipeline is a mixture of hydrocarbons and diluents such as nitrogen and carbon dioxide. The composition of the mix