Transporting natural gas thousands of miles through pipelines is the safest method of transportation. The transportation system for natural gas consists of a complex network of pipelines, designed to quickly and efficiently transport natural gas from its origin, to areas of high natural gas demand.
There are three major types of pipelines along the transportation route: the gathering system, the interstate pipeline system, and the distribution system. The gathering system consists of low pressure, small diameter pipelines that transport raw natural gas from the wellhead to the processing plant.
Pipelines are interstate or intrastate. Interstate pipelines are similar to the interstate highway system: they carry natural gas across state boundaries, and in some cases, across the country.
Interstate pipelines consist of a number of components that ensure the efficiency and reliability of a system that delivers an important energy source year-round, 24 hours a day.
Transmission pipes can measure anywhere from 6 to 48 inches in diameter. The actual pipeline consists of a strong carbon steel material, engineered to meet vigorous standards.
The pipe is also covered with a specialized coating to ensure that it does not corrode once placed in the ground. The purpose of the coating is to protect the pipe from moisture, which causes corrosion and rusting.
Natural gas is highly pressurized as it travels through an interstate pipeline. To ensure that the natural gas flowing through any one pipeline remains pressurized, compression of this natural gas is required periodically along the pipe. This is accomplished by compressor stations, usually placed at 40 to 100 mile intervals along the pipeline. The natural gas enters the compressor station, where it is compressed by either a turbine, motor, or engine.
In addition to compressing natural gas to reduce its volume and push it through the pipe, metering stations are placed periodically along interstate natural gas pipelines. These stations allow pipeline companies to monitor the natural gas in their pipes.
Interstate pipelines include a great number of valves along their length. These valves work like gateways; they are usually open and allow natural gas to flow freely, or they can be used to stop gas flow along a certain section of pipe.
To ensure that all customers receive timely delivery of their portion of the gas, sophisticated control systems monitor the gas as it travels through all sections of what could be a very lengthy pipeline network. To accomplish the task of monitoring and controlling the natural gas that is traveling through the pipeline, centralized gas control stations collect, assimilate, and manage data received from monitoring and compressor stations along the pipe.