Stainless Steel U-tube 1) Material: 304,316 and so on. 2) Standard: ASTM/ ... AISI/DIN/JIS 3) OD : 1/2''-48'' SEAMLESS STAINLESS STEEL ... , UNS,CSA, DGN, AS, NF and GOST4) Applications: petroleum, chemical industry, chemical fiber, smelt, medical machinery, papermaking, heat preservation and refrigeration ...