Manufacturing method of reinforced layer

A manufacturing method for manufacturing a reinforced layer constituting a high-pressure tank, the manufacturing method comprising:

• a first forming step of forming a cylindrical pipe portion made of fiber reinforced resin and extending in an axial direction of the high-pressure tank, the pipe portion including a first end portion including a first end in the axial direction and a second end portion including a second end in the axial direction, the pipe portion being formed to have a first stepped portion formed in the first end portion such that the first stepped portion projects outwardly at a position distanced from the first end in the axial direction by a first distance determined in advance;
• a second forming step of forming a first dome portion made of fiber reinforced resin and having a hemispherical-surface shape, the first dome portion including a first top portion and a first bottom end portion forming a first opening, the first bottom end portion having an inside diameter larger than an outside diameter of the first end;
• a third forming step of forming a second dome portion made of fiber reinforced resin and having a hemispherical-surface shape, the second dome portion including a second top portion and a second bottom end portion forming a second opening, the second bottom end portion having an inside diameter larger than an outside diameter of the second end;
• a first placing step of placing the first end inside the first dome portion by moving, in the axial direction, at least either of the first dome portion and the pipe portion until the first bottom end portion abuts with the first stepped portion;
• a second placing step of placing the second end inside the second dome portion by moving, in the axial direction, at least either of the second dome portion and the pipe portion;
• a first joining step of, after the first placing step, joining the pipe portion to the first dome portion;
• and
• a second joining step of, after the second placing step, joining the pipe portion to the second dome portion.