Finite Element Analysis of Sealing Performance of Rubber D-Ring Seal in High-Pressure Hydrogen Storage Vessel

Abstract

Sealing structures of high-pressure hydrogen storage vessel are always considered as one of the significant components. This paper aims to study the sealing performance of the combined sealing structure composed of a rubber D-ring and a wedge-ring used in high-pressure hydrogen storage vessel by elucidating the swelling mechanisms due to dissolved hydrogen. Comparisons of the sealing performance between the D-ring and the O-ring are made in terms of the effects of some important factors including the wedge-ring, hydrogen pressure and swelling. Three aspects of conclusions are obtained by FEA: (1) The wedge-ring with a wedge angle 45° is the most suitable, compared with the angles 30° and 60°, irrespective of the shape of rubber rings. (2) The peak contact stress for the D-ring seal is larger than that for the O-ring seal under hydrogen pressure range 0–100 MPa. (3) The O-ring seal could be replaced well by the D-ring seal, whereas the design height of the seal groove should be larger for the D-ring seal than for the O-ring seal due to swelling effect, in order to prevent the D-ring seal from extrusion through the upper side of the seal groove.