Duplex Pipe/Duplex Tube/Seamless Duplex Pipe Standards: ASTM/ASME A789/SA789, A790/SA790,A450,A530Material: UNS S32750,2205,UNS S31803(Cr22Ni5Mo3);UNS S31500(Cr18NiMo3Si2)Duplex stainless steel tubes and pipes are with high mechanical strength, good elongation and weld ability which needs no pre-heating before welding and heat treatment after welding, low thermal expansion, excellent resistance to stress corrosion cracking, pitting and crevice corrosion, and high resistance to general corrosion in different environments. Duplex stainless steel tubes and pipes are applied to heat exchangers in refinery industries, petrochemical plants, paper and pulp industries, sugar and beverage industries.