Abstract: A flange connection with a disc-shaped base body of incompressible material disposed between mutually facing planar sealing surfaces of flanges which are to be assembled and connected to one another, the base body being formed with a central bore having a diameter matching an inner diameter of the flanges and formed with at least one annular slot, comprising a compressible sealing insert formed of expanded graphite and received in the annular slot, the sealing insert, before assembly and connection of the flanges, being higher by an amount .DELTA.h than the depth of the annular slot, .DELTA.h being of such value and the annular slot being of such volume that when the sealing insert is compressed more than 100 N per mm.sup.2, with the flange engaging the base body and utilizing the spring-back resilient properties of the sealing insert, the sealing insert after the flanges are assembled, is enclosed on all sides by defining surfaces of the circular slot and by means of the sealing surfaces of the flanges.