Straight tube is to point to weld and steel pipe vertically parallel tube. General also called straight seam welded pipe or straight steel tube joints [1]. Straight tube is through the high frequency welding unit will certain strip steel strip coil specifications and USES the straight welded seam. Straight tube with nominal diameter specifications, said according to wall thickness can be divided into thin wall straight tube and thick wall straight tube two kinds. According to shape can be divided into round, square or profile tubes, etc.

Straight tube is used mainly in the tap water engineering, petrochemical industry, chemical industry, electric power industry, agriculture irrigation, the urban construction. For liquid transportation use: Water supply, water drainage. As gas with gas, steam, conveying and liquefied petroleum gas (LPG). As with: Be piling tube structure, bridge; Wharf, road, building structural tube, etc.