GOST/ГОСТ 12820-80 Standard,Steel plane welded flanges for Pnom from 0,1 to 2,5 MPa (from 1 to 25 kgf/cm2) Design and dimensions Download the PDF    PDF file: GOST 12820 Standard Steel plane welded flanges pn 0.1 20 mpa design Dimesions weight   GOST/ГОСТ standard flange dimension and weight  GOST/ГОСТ 12836-67 Flange Standard Blind Flange Dimensions