Encyclopedia
Flange
Flange (flange): flat circular end of a pipe or connecting part, located perpendicular to their axis, with bolt holes uniformly arranged around the circumference
Source: "GOST R ISO 2531-2008. Cast iron pipes, fittings, valves and their connections for water and gas supply. Technical conditions"
(approved by Order of Rosstandart dated 25.12.2008 No. 662-st)