,uency longitudinally welded pipe production line is mainly used for the production of square, rectangular, deformed, carriage steel plate, etc. of the corresponding size. Every unit of the production line not only digest and absorb the advantages of like e at home and abroad ,but also carry on innovation through connecting with national and international conditions. The production line takes the lead throughout China in design, manufacture, operation and maintenance. Adopting reasonable roll pass design, the line can manufacture welded pipes with good machining and high precision assembling.