Abstract: The invention resides in a flange joint for use in the assembly of pipings from pipe elements. A fixed sealing flange is welded to each of the opposite ends of two adjacent pipe lengths and/or pipe fittings. Each sealing flange has two annular concentric contact surfaces on the back thereof separated by one relatively deep and broad circular groove in said back, or by a number of relatively deep but narrow annular concentric grooves. A loose flange is threaded on to each of the opposite ends of said pipe lengths or fittings behind the fixed sealing flange, such loose flange having a greater diameter than the sealing flange. The flange joint is tightened by means of bolts and nuts received in a number of holes through the part of said loose flanges located beyond the circumference of the fixed sealing flanges, causing the loose flanges to engage said annular concentric contact surfaces of the sealing flanges. The outer one of said contact surfaces is to be slightly depressed in relation to the inner one.