What type of pipelines may be used as a common carrier or a contract carrier in gas systems?

Transmission pipelines are the type of pipelines that may be used as common carriers or contract carriers in gas systems. These pipelines are designed for the long-distance transportation of natural gas from production areas to distribution points, often spanning large geographical areas.

A common carrier is a service that must accept all customers who request service under the same terms, while a contract carrier may transport gas under specific agreements with designated shippers. Transmission pipelines operate at high pressures and are typically larger in diameter compared to gathering and distribution lines, allowing for substantial volumes of gas to be transported efficiently.

Gathering pipelines primarily collect gas from production sites and transport it to processing facilities or transmission lines; they usually do not serve as common carriers. Distribution pipelines are smaller and distribute gas to end-users, such as homes and businesses; their function is to move gas closer to the consumer rather than transport it over long distances. Branch pipelines are typically secondary lines that extend from distribution networks and are not designed for the primary purpose of common or contract transport.