Abstract: A pipe flange coupling having a carbon steel body and flange with a bore extending through the body and flange and a bolt circle in the flange, a lining throughout the entire length and circumference of the bore, and a sealing surface on the flange radially inward of the bolt circle and radially outward of the bore, the sealing surface and lining being of corrosion resistant metal fusion welded to each other and to the flange and bore and providing a structurally unitary body which meets the pressure code and also protects the carbon steel from corrosion.