A pipeline is more than just thick, high-grade steel in the ground. Compressor stations, located about every about 40-100 miles along the interstate transmission system, are the key to making a pipeline work. The compressors compress the natural gas and send it – at an average speed of about 10-20 mph – through the pipeline. Compressors stations ensure that the gas continues to flow at a constant rate.
For a pipeline company to manage its gas pipeline system efficiently, it must know how much gas is in the system at all times. With some interstate pipeline systems extending 1,000 or more miles, this can be a daunting task. Pipeline companies use metering stations to measure all natural gas entering or exiting the pipeline system. Some meter stations also regulate gas pressure and delivery volumes. Pressure regulation equipment ensures that gas delivered into or out of a pipeline system is maintained within a specified safe pressure range.
Pipeline companies install valves along a gas pipeline system to control the flow. The valves may be spaced as close together as every five miles or as far apart as 20 miles according to standards established by safety codes. The valves normally are open, but when a section of pipeline requires maintenance, operators close the valves to isolate that section of the pipeline. Once isolated, the maintenance crew can vent, or release, the gas from that section of the pipeline and proceed with its repairs.
Storage facilities are another way the industry can help ensure that gas is available when needed – on the coldest winter day or the hottest summer day or when there is a disruption of supply because of an emergency, such as a hurricane. Most natural gas storage fields are depleted gas reservoirs; others are underground caverns in salt domes. Because natural gas storage is dependent on geological formations, storage cannot be placed everywhere.
1American Gas Association. “America’s Energy: Natural Gas Utilities. Delivering America's Energy.” 2016.