Pipeline pipe is the abbreviation of steel pipe used to transport oil, product oil, natural gas, water and other pipelines in the oil and natural gas industry. The oil and gas pipelines are mainly divided into three types: main pipeline, branch pipeline and urban pipeline network. The general specification of main pipeline is ∮ 406-1219mm, wall thickness is 10-25mm, and steel grade is x42-x80. The general specification of branch pipeline and urban pipeline network is ∮ 114-700mm, wall thickness is 6-20mm, and steel grade is x42-x80.
There are welded steel pipes and seamless steel pipes in the pipeline. The use of welded steel pipes is more than that of seamless steel pipes.
1. Steel grade and chemical composition of pipeline
The steel grades of pipeline pipes from low to high are: a25, a, B, X42, X46, X52, X60, X65, X70 and X80.
2. Water pressure and nondestructive requirements of pipeline
The water pressure test should be carried out one by one for the pipeline, and the standard does not allow the replacement of water pressure without damage, which is also a big difference between the API standard and the Chinese standard.
PSL1 does not require NDT, and PSL2 shall be NDT one by one.
3. Pipeline standard
The standard of pipeline is API 5L 《Specification for pipeline steel pipe》, but in 1997, China issued two national standards for pipeline pipe: GB / T9711.1-1997 《Technical conditions for delivery of steel pipe for oil and gas industry Part 1: class a steel pipe》 and GB/T9711.2-1997《Technical conditions for delivery of steel pipe for oil and gas industry part 2: Class B steel pipe》, which are equivalent Developed in API 5L, many domestic users require to supply according to these two national standards.