A pipeline traverses through various diverse locations which are difficult to approach during regular operation. For the construction of the pipeline enormous chunk of land is temporarily acquired by the Pipeline Operator from the land owners. Once the pipeline is buried, land is returned to the owners for their use such as agriculture ect. Which limits the accessibility to the pipeline in due course of time. Therefor, pipelines are required to be constructed such that it requires minimal human interference during operation and ensures high level of safety & integrity throught its design life. The onus to fulfill such high quality and reliability standard rests on the first building block of any pipeline i.e. line pipes. Line pipes are defined as welded or seamless pipes, available with the end a plain, beveled, grooved, cold expanded, flanged, or threaded; used for the construction of pipelines principally used to convey gas, oil or water.
Types of line pipes :
Based on the fabrication processes, generally following types of line pipes are being used in hydrocarbon pipeline sistem.
Process of manufacture Size inches (mm)
Seamless (SMLS) 4.5 to 16
High Frequency Welded (HFW) 4.5 to 20
Submerged Arc Longitudinal Welded (SAWL) 16 to 56
Submerged Arc Helical Welded (SAWL) 18 to 56