Patent attributes
A joint part includes a connection part weldable on the tank and a tube part including an inner circumferential face. An inner tube is fitted inside and in contact with the inner circumferential face. The tube and the inner tube include materials having different swelling rates when exposed to the fuel to be stored in the tank. An end of the tube, and an end of the inner tube corresponding in an axial direction with the end of tube, include slopes therearound in contact with each other. The slopes are inclined from the axial direction. When the tube and the inner tube swell due to being wet with the fuel, the slopes have a relative displacement in the axial direction and in a radial direction of the tube and the inner tube, with contact therebetween.