... heat exchanger 2material:0Cr18Ni9,1Cr19Ni10,00Cr19Ni10,0Cr18NI14Mo3 etc. carbon steel tube 1. Reference standard : ASTM, JIS, EN,API2. ... for boiler c: Water delivery 4. advantage :a: without oxidation both outer wall and inner wall b: under ... high pressure without leakage c: high-precision d: high finish e ... 2.production process3.package4.stock carbon steel tube