... Steel Welded Pipes/Tubes passed Nondestructive Electric Test. The production technology of ASTM A312 Big Diameter Stainless Steel ... and Label5) Applied field: Decoration, Heat-Exchanger, Condenser Tubes, Sanitation, food industry , Petroleum and Gas Industry and Liquird ... or according to customers' requests. ASTM A312 Big Diameter Welded Stainless Steel Pipes, Tubes and Tubings for Liquid Delivery