Abstract: A pressure vessel includes a liner having an end wall assembly formed by connecting two rigid end wall members at a fixed distance from each other by a connecting member, and an elastic peripheral wall sheet fixed to the two end wall members so as to enclose a space between them. The two end wall members are made of aluminum alloy by an extrusion process. The connecting member is a pipe made of aluminum alloy by an extrusion process and having a large number of communicating holes in the pipe wall. The peripheral wall sheet is made of aluminum foil and is formed in a cylindrical shape so as to enclose the space between the two end wall members. Around the liner are provided a helical reinforcing layer and a hooped reinforcing layer which are both made of FRP. This pressure vessel is lightweight and can be easily produced at a low cost.

Abstract: A dust boot for a universal joint covering two joint elements having largely curved corner portions in the outer peripheral surface thereof near their joint portion, comprises a resilient annular covering portion for covering the joint portion of the universal joint and two annular end portions which are integrally formed with the covering portion in axially both ends thereof. The annular end portions are mounted on the two joint elements near their joint portion. Since the area of an open end of the dust boot mounted on the joint element having largely curved corner portions is made smaller than the cross sectional area of the outer peripheral surface of the joint element, specifically only the curvature of the open end of the dust boot corresponding to the largely curved corner portions of the joint element is made smaller than that of the corner portions of the joint element, the dust boot can be closely mounted on the joint element with excellent sealing effect.