Usually, the main transmission pipeline specifications is for ∮406～1219mm,wall thickness for 10～25mm,steel grade for X42～X80,the regional transportation pipeline and the urban pipeline usually specifications is for ∮114～700mm,wall thickness for 6～20mm,steel grade for X42～X80. In addition, according to the manufacture process and the tube bloom used different shapes, the line pipe can be divided into:
- seamless steel pipe
- welded steel pipe
Line pipe standards
Line pipe execution standard is API 5L 《The pipeline steel pipe standard 》, however, China issued two line pipe national standards in 1997.they are GB/T9711.1-1997《The oil and gas industry conveying pipe and delivery technology conditions the first part: level A steel tube 》and GB/T9711.2-1997《The oil and gas industry conveying pipe and delivery technology conditions the second part: level B steel tube》. The two standards are equivalent to API 5L, thus, domestic many users require supply according the two national standards.
Line pipe steel grade from low to high is divided into: A25、A、B、X42、X46、X52、X60、X65、X70 and X80.
