When gas is transported in pipelines, consideration must be given to the control of the formation of hydrocarbon liquids in the pipeline system. Condensation of liquid is a problem in metering, pressure drop and safe operation. Condensation of liquid can also be a major problem with two-phase flow and liquid slugging. To prevent the formation of liquids in the system, it is necessary to control the hydrocarbon dew point below the pipeline operating conditions. Since the pipeline operating conditions are usually fixed by design and environmental considerations, single-phase flow can only be assured by removal of the heavier hydrocarbons from the gas.
