... steel and alloy steel 3.Processing thchnic:forged ANSI CLASS300 WELDING NECK flange1.Size :1/2"(DN15)-36"(DN900)2. ... production line , equipment and introduce the latest technique to manufacture various kinds of flange ,such as slip-on, welding -on ,welding neck ... ,plate ,blind , lap joint , threaded and socket welding .About pipe fitting ,we can ...