... up to X80,Φ406mm-Φ1422mm ,with Yangzhou Tongya Pipe Co.,Ltd.The Spiral Welding Pipe Mills designed and manufactured by our ... style with continuous production capability.Diameter range of final pipe line products could cover anything between Φ219mm and Φ2800mm.Our products ... GB9711.1,GB9711.2 Standards. Our company also assists pipe line manufacturing firms in layout,planning and design of products and ...