... ,GB9711.2 SSAW MILL(Φ219mm-Φ3000mm)Spiral shaped,double–submerged arc welding pipe production lines (Spiral Weld Pipe Mills Φ219mm-Φ3000mm ) ... . Very recently,we signed a contract of double-submerged arc spiral welding pipe mill with domestically leading high iron grade up ... X80,Φ406mm-Φ1422mm ,with Yangzhou Tongya Pipe Co.,Ltd.The Spiral Welding Pipe Mills designed and manufactured by our company have ...