For manufacture of boilers, superheaters of ships, and I,II,III ranks pressure system pipelines, hydraulic gastransportion and bulk chemicals. Standard： CCS Regulations of Material and Welding----China Classification Society GB／ T531 2-------Chinese National Standard GB／T14976-------Chinese National Standard DNV Regulations------Det Norske Veritas Approval of Manufacturer LR Regulations--------Lloyd Regulations of Shipping ABS Regulations--------American Bureau of Shipping GL Regulations--------- Germanischer Lloyd BV Regulations---------Bureau Veritas KR Regulations---------Korean Register of Shopping NK Regulations---------Nippon Kaiji Kyokai RINA Regulations---------RINA Main Steel Tube Grade： 320,360,41 0,00C rl 7Nil4Mo2,0C r18Ni9Ti etc. Other grade can also be provided after consulting with customers .