LSAW steel pipe (straight seam submerged arc welded steel pipe) is a steel pipe made from a single medium thick plate as raw material

LSAW STEEL PIPE

一：Difine

LSAW steel pipe (straight seam submerged arc welded steel pipe) is a steel pipe made from a single medium thick plate as raw material, which is pressed and formed, welded and expanded using double-sided submerged arc welding technology. The finished diameter range is from Ø 406.4 to Ø 1422.4mm, with a maximum length of 12.2m, in compliance with international standards such as ISO3183-3 and API Spec 5L.

 According to the forming method, it is divided into three types: UOE, JCOE, and HME. It adopts a longitudinal single weld structure and mechanical expansion process. The weld is treated with both pre welding and precision welding, and is suitable for the construction of oil and gas pipelines in high-altitude areas, seabed areas, and densely populated areas [1] [3].

 The steel pipe production equipment includes an external submerged arc welding machine and an internal submerged arc welding machine, and is equipped with auxiliary devices such as an external wall crushing mechanism and a rotating adsorption head, which can mechanically collect welding debris

二：Scope of application and processing method

LSAW steel pipes have a wide range of finished specifications, with good toughness, plasticity, uniformity, and density of welds. They have the advantages of large pipe diameter, thick pipe wall, high pressure resistance, low temperature resistance, and strong corrosion resistance.

 When constructing high-strength, high-quality long-distance oil and gas pipelines, most of the required steel pipes are large-diameter thick walled straight seam submerged arc welded pipes.

 According to API standards, when passing through Class 1 and Class 2 areas such as high-altitude regions, underwater areas, and densely populated urban areas in large oil and gas pipelines, straight seam submerged arc welded pipes are the only designated pipe types.

According to different molding methods, it can be divided into:

UOE steel pipe: After pre bending at the edge, a single steel plate undergoes processes such as U-forming, O-forming, internal welding, external welding, and mechanical cold expansion.

JCOE steel pipe: refers to the process of pre welding, forming, and cold expansion after welding according to "J-C-O-E"

HME steel pipe: formed by core rod rolling method according to "C-C-O", welded and then subjected to cold expansion and other processes.