The paper presents recently published literature research on the tightness and strength of flange joints. These could influence both the calculation and the maintenance of flange joints. Some of the research results have been compared to normative stipulations currently used in the calculation of flange joints. The presentation covers: – the influence of sealing gasket design and screw load on sealing; – the influence of creep on screw relaxation, and thereby on gasket sealing; – cracking in flange joints; – the influence of an additional axial force of flange joints on the rotation and on the deformation of flange joint components; – flanges without sealing gasket; – the influence of the method of flange joint bolt tightening on the uniformity of bolts loading and tightness.