... :316,304 4.apply:boiler,heat-exchanger,condenser 304 seamless and welded steel tubeOur company is professionally specializing in seamless pipe ... ,316L,TP317L,TP321,321H,TP347,TP347H,etc.2. standard:ASTM A269,ASTM A312,ASTM A213,GB2270-80, GB/T14975-94,GB/T14976-94 ... PipeSize(mm)O.D.: 6-840mm W.T.: 1-60mmGrade and Chemical Composition(%) standardASTM A312/A312MASTM A249/A249MASTM A688/A688MJIS G3468item ...