The Application of Line Pipe


The American Petroleum Institute (API) is comprised of manufacturers and end users working together to define the quality and safety standards for products and services associated with the oil and gas industry. The manufacturing standards for Oil Country Tubular Goods (OCTG), such as line pipe, are established by the API. Line pipe standards are also set by the ASTM International, an international standards organization. Line pipe grades are manufactured according to the following specifications: API 5L, ASTM A984, and ASTM A1024.


Line pipe is used for transporting natural gas, petroleum, oil, and water. The three types of line pipe are stainless steel line pipes, welded carbon steel line pipes and seamless line pipes.



  1. Stainless Steel Line Pipes: Stainless steel line pipes are corrosion resistant and offer high durability, strength, and machinability.
  2. Welded Carbon Steel Line Pipes: Welded carbon steel line pipes are often used in buildings, sprinkler and irrigation systems, water wells and machinery.
  3. Seamless Line Pipes: Seamless line pipes offer a higher ability to withstand pressure than welded carbon steel line pipes.


Line pipe offers the strength and durability necessary to withstand high pressures. However, to ensure safety and reliability, all line pipes used in any given pipeline service must be carefully evaluated. Important factors to be considered include the chemistry of the steel, the degree of strength, the toughness level and the dimensions.



U.S. manufacturers make up a strong sector in the carbon steel line pipe market. Carbon steel line pipe is used in the following markets:


  • Oil and Gas Pipelines: Oil and gas pipelines are pipelines used to transport crude and refined petroleum and fuel, such as oil, biofuels and natural gas. These pipelines are often used to transport materials from the production area to a storage facility or to the larger main pipeline.
  • Mineral Slurry Pipelines: Mineral slurry pipelines are pipelines engineered for transporting ore and mining waste across long distances. Applications include but are not limited to interplant operations and the transportation of wastewater, untreated water and water for urban water supply systems.
  • Water and Sewage Pipelines: Water and sewage pipelines are pipelines designed to move water or sewage. These services include water treatment stations, pumping stations, water mains, and onshore and offshore sewage pipelines.


Line pipe comes in a variety of lengths, sizes, grades, and diameters. Line pipe diameters range from 2 inches to 48 inches. The size and/or diameter of line pipe vary, depending on the amount of gas or liquid the pipe is designed to transport.



End users must consider the volume of the transported materials when purchasing line pipe. For instance, a pipeline used to deliver or take gas from a mainline typically requires smaller piping than a principle pipeline used to deliver natural gas. End users must also take into account the degree of pressure at which the materials will be transported. The maximum operating pressure of a pipeline will determine the thickness of the line pipe needed.


It is important to pay close attention to published specifications, evaluation requirements and federal guidelines when purchasing line pipe for any service. Taking the proper steps will prevent potentially hazardous situations, and ensure that each pipeline design operates both properly and optimally.

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