Pipeline Types and Infrastructure

Pipelines are categorized and regulated by what they transport and where they go.   Understanding these categories is important because they determine how pipelines are constructed and regulated.  It is also helpful to remember that the term gas transmission pipeline often includes all parts of the physical facilities through which gas moves in transportation, including pipe, valves, and other appurtenance attached to pipe, compressor units, metering stations, regulator stations, delivery stations, holders, and fabricated assemblies. So when you think pipelines, think pipelines and infrastructure. 

Pipelines transport a variety of fuels including gasoline, natural gas, propane, hazardous liquids, diesel and jet fuel.  Natural gas, flammable gas, or gas which is toxic or corrosive (Reference 49 CFR 192.3) are normally compared to air in terms of density. The specific gravity of air is 1.0.  Any gas with a specific gravity less than 1.0 (such as natural gas) will rise and usually disperse while those gases having a specific gravity greater than 1.0 will fall and collect near the ground or in low lying areas. 

Discussions about gas pipelines generally include:

  • Hazardous Liquid Pipelines: carry fuels such as gasoline, diesel, jet fuel and 
  • Gas Pipelines: carry natural gas and propane
The development of Marcellus Shale Gas has added new dimensions to those discussions.  Marcellus Shale is considered an unconventional gas.  The distinction between conventional and unconventional gas resources is important in terms of the expansion and adoption of new pipeline terms, definitions of use and applicable regulations.  The concurrent need for increasing the capacity of current infrastructure with new pipeline infrastructure to transport Marcellus and Utica unconventional gases raised questions about safety and siting regulation of these new Marcellus pipeline classifications by communities impacted by their appearance in their landscapes. Traditionally referenced types pipelines and Marcellus Shale pipelines are included on this discussion.   

Wellhead to Consumer Pipeline Infrastructure

Understanding the components of pipeline infrastructure is helpful in understanding the range and definition of pipelines.  A discussion of pipeline infrastructure is incomplete without starting at the source, the Wellhead and it’s location, the well pad.  This infrastructure discussion starts at a Marcellus Shale well pad.
  • Well Head and Well Pad
  • Production Lines
  • Gathering Lines
  • Gas Processing Plants
  • Gas Transmission Pipelines
  • Compressor Station
  • Valves Smart Pig  & Smart Pig Launchers
  • Citygate
  • Distribution Lines
  • Water Lines (Fresh Water and Flowback)