WN Flanges 304, 304L, 316, 316L, 321, S31803 Certification: BV, ABS, GL, PED, ISO9001 Kind :WN, SO, PL, SW, LJ, BL Slip On Flanges - ANSI B16.5 Stainless Steel 304L,316L ect. Standard Chinese Flange Used in Pipeline,Transport ISO9001-2008. Stainless Steel Flanges SpecificationASTM A 240,AI82DimensionANSI B 16.5GradeTP304,304L,304H,316, 3I6L,316H,317,317L, 321, 347RangeSORF, BLRF, SWRF, WNRF, ...