Longitudinal welded pipe, the steel pipe made of hot-rolled or cold-rolled steel plate or steel strip by coil welding is longitudinally welded on the welding equipment, and the pipe obtained is called longitudinal welded pipe. (it is named because the welded joint of steel pipe is in a straight line).

LSAW steel pipe and ERW steel pipe are two kinds of Longitudinal welded pipe. LSAW can be divided into UOE, RBE and JCOE steel pipes according to their different forming methods There are two kinds of straight seam welded steel pipe according to the specified wall thickness: ordinary steel pipe and thickened steel pipe. According to the pipe end form, the steel pipe can be divided into two types, with thread and without thread. The length of the straight seam of the steel pipe with a diameter of 14 meters is not determined, and the welding of the steel pipe with two straight edges is not required.

The specification of longitudinal welded steel pipe is expressed by nominal diameter and wall thickness. According to the wall thickness, it can be divided into thin-walled straight seam pipe and thick wall straight seam pipe. According to the shape, it can be divided into round, square or special-shaped pipe, etc.

Straight seam welded steel pipe is mainly used in water supply engineering, petrochemical industry, chemical industry, electric power industry, agricultural irrigation and urban construction.

For liquid transportation: water supply and drainage.

For gas transportation: gas, steam, liquefied petroleum gas.

For structure: pile driving pipe, bridge, wharf, road, building structure pipe, etc.