What are the main types of pipeline pipes?

Divided by manufacturing process into seamless steel pipe (SMLS) and welded steel pipe (Welded); Welded steel pipes are divided into spiral submerged arc welded pipes (SSAW), straight seam submerged arc welded pipes (LSAW), and high-frequency straight seam welded pipes (ERW). The main types of oil and gas steel pipes are these four, each with a suitable diameter and pressure range.