Pressure vessel liner and method for manufacturing pressure vessel liner

A method for manufacturing a pressure vessel liner, the method comprising:

• a molding step of molding a pair of first liner members, in a bottomed cylindrical shape, and a second liner member in a bottomless cylindrical shape, the second liner member having opposing ends and a center, with opposing side portions on opposing sides of the center;
• and
• a joining step of joining, respectively, the pair of first liner members with the second liner member at the opposing ends, of the second liner member, in an axial direction of the second liner member,
• wherein the second liner member is molded in the molding step, with a resin injected such that a wall thickness of the second liner member gradually decreases from the center outwardly, in an axial direction of a cavity in a molding die toward the respective opposing ends of the second liner member, such that the wall thickness gradually decreases over a least a portion of each side portion;
• wherein the cavity has a distance between walls gradually decreasing from the center toward the opposing ends of the second liner member, and the cavity communicates with a gate, through which the resin is injected, at the center.