一. Different classification
1. Straight seam steel pipe: divided into metric electric welded steel pipe, electric welded thin-walled pipe, transformer cooling oil pipe
2. Seamless steel pipe: seamless pipe is divided into hot-rolled pipe, cold-rolled pipe, cold-drawn pipe, extruded pipe, pipe jacking, etc. According to the cross-sectional shape, the seamless steel pipe is divided into two types: round and special-shaped.
二：Second, the concept is different
1. Straight seam steel pipe: Straight seam steel pipe is a steel pipe whose weld seam is parallel to the longitudinal direction of the steel pipe.
2. Seamless steel pipe: A steel pipe made of a single piece of metal without seams on the surface is called a seamless steel pipe.
二. Different uses
1. Straight seam steel pipe: Straight seam steel pipe is mainly used in water engineering, petrochemical industry, chemical industry, electric power industry, agricultural irrigation, and urban construction. For liquid transportation: water supply, drainage. For gas transportation: gas, steam, liquefied petroleum gas. For structure: for piling pipe, for bridge; for wharf, road, building structure, etc.
2. Seamless steel pipe: Seamless steel pipe has a hollow section and is widely used as a pipeline for transporting fluids, such as pipelines for transporting oil, natural gas, gas, water and certain solid materials. Compared with solid steel such as round steel, the steel pipe is lighter in weight when the bending and torsional strength is the same, and is an economical section steel.
