Abstract: A set of flanges, an installation including the set of flange and a method for providing the installation are disclosed. The set of flanges includes a first annular flange with a first front side and a second annular flange with a second front side. Each flange includes a plurality of through holes for mounting the flanges with the first side facing the second side. The first and the second sides are shaped such that the annular toe surface section of the first front side is adapted to provide an annular toe contact region with the annular toe surface section of the second front side and the annular heel surface section of the first front surface is adapted to provide annular heel contact region with the annular heel surface section of the second front side whereby an intermediate annular gap is provided between the annular toe contact region and the annular heel contact region.