Hollow product, method and apparatus for manufacturing the hollow product, and fluid transporting system using the hollow product

An apparatus for manufacturing a hollow product including a hollow member and another member that are joined together, comprising:

• a driving device that rotates at least one of the hollow member or the another member relatively to the other after the another member is inserted into the hollow member so that an outer circumferential surface of the another member faces an inner circumferential surface of the hollow member;
• a presser member applying a radial pressure to a position where the inner circumferential surface of the hollow member faces the outer circumferential surface of the another member for joining together the circumferential surfaces thereof by a friction welding while the circumferential surfaces of the hollow member and the another member are rotated relatively to each other, and
• a controller that controls a movement of the presser member so as to perform a spinning operation on the at least one of the hollow member or the another member and that controls a radial force exerted by the presser member to join the hollow member and the another member together by a friction welding continuously.