... from stock 4.API, TUV...certificate welding neck flange, BS 32931.specificationStandards: ANSI(ASME), AWWA, DIN, EN1092, GOST, ... 070M20 BS4360GR.43A BS1503-164 GR.490 BS 1503-224 GR.410 BS 1503-304S11304S31 321S31 316S31 316S11 10 BS10 ... WNBS1501-161 GR.B AND C BS1633GR.B BS 1503-240GR.240 BS 1503-620 BS3604 11 ISO 7005-1 ... STANDARD DN10-4000 PN2.5,6,10,16,20,25,40,50,110 ...