High-quality molded head factory, professional molded head plant, carbon steel molded the head plant http://www.hebftc0.com/ telephone 0317-8210122, the phone 13722724665 molded head factory which methods to calculate it, a head diagram Figure in CD, AB head straight edge, ED, FB represents a small arc parts, EF is the big arc. The head longitudinally welded patchwork for Class A welds. JB/T4730.2-2005 standard specifies testing level for the AB grade longitudinal stitching weld K ≤ 1.03. This is detailed data.