... , 600Lbs, 900Lbs, 1500Lbs, 2500Lbs, /PN6,PN10,PN16,PN20,PN25,PN40/ Class A, B, C, D, EstandardASME B16.5, ASME B16.47 ... -1500A4.BS FLANGESStandard: BS 4504 SEC 3.1 :Standard: BS 10 : Welding neck Flanges, Plate Slip-on Flanges, Screwed Boss Flanges ... neck Flanges(GOST12821-80); Steel Butt-Welded Flanges GOST12821-80Pressure Class:PN=0.6--PN10,0 (100 /2)SIZE: 1/2 ...