American Standard steel pipe21*2.5,A106B630*7.5Steel pipe,Chinese steel pipe21*2Steel Pipe

Scope ASTM A53 is Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless. ASTM A106 is Standard Specification for Seamless Carbon Steel Pipe for High-Temperature Service. API 5L is Specification for Line Pipe. Application A 53 is a general steel pipe spec which covers galvanized pipe and black pipe. It is available in Type S (seamless), Type E (ERW, electric resistance welded longitudinal seam), and Type F (furnace welded). A106 Gr. B is intended for high temperature service (up to 750 Deg F). It just applies to seamless steel pipe with killed steel. Pipe of NPS 1 1/2” and under may be either hot finished or cold drawn. Unless specified, pipe on and over NPS 2″ shall be furnished hot finished, while A53 and API 5L are not. API 5L Gr. B (PSL-1) is mainly developed for Line pipes used in conveying gas, oil, and water in oil and gas industry. Either seamless steel pipe or welded pipe is OK.