our ngl pipelines & services business segment includes 22 natural gas processing facilities and related ngl marketing activities; approximately 19,900 miles of ngl pipelines; ngl and related product storage facilities; and 16 ngl fractionators. this segment also includes our lpg and ethane export terminals and related operations.
purity ngl products (ethane, propane, normal butane, isobutane and natural gasoline) are used as feedstocks by the petrochemical industry, by refineries in the production of motor gasoline and by industrial and residential consumers as fuel. ethane is primarily used in the petrochemical industry as a feedstock for ethylene production, one of the basic building blocks for a wide range of plastics and other chemical products. propane is used both as a petrochemical feedstock in the production of ethylene and propylene and as a heating, engine and industrial fuel. normal butane is used as a petrochemical feedstock in the production of ethylene and butadiene (a key ingredient of synthetic rubber), as a blendstock for motor gasoline and to produce isobutane through isomerization. isobutane is fractionated from mixed butane (a mixed stream of normal butane and isobutane) or produced from normal butane through the process of isomerization, and is used in refinery alkylation to enhance the octane content of motor gasoline, in the production of isooctane and other octane additives and in the production of propylene oxide. natural gasoline, a mixture of pentanes and heavier hydrocarbons, is primarily used as a blendstock for motor gasoline or as a petrochemical feedstock.