To make a fluid pipe easily flexible of extension/contraction without using a large-sized closed case and cutting device, and improve cut off work accuracy of an existing fluid pipe without damage to a packing between the fluid pipe and a body of equipment and repair of an external peripheral surface of the fluid pipe.

A pair of supporters 40a, 40b divided in a pipe axial direction are mounted so as to cooperate with a rotary sleeve 10, and by providing a radial direction bracing means 42 in these supporters 40a, 40b, deflection in a radial direction is regulated relating to the external periphery of both bodies 5, 5 of equipment fixedly provided in the external periphery of an existing fluid pipe 1, so that the supporters 40a, 40b cooperating with the rotary sleeve 10 can regulate deflection in the radial direction relating to the external periphery of both the bodies 5, 5 of equipment fixedly provided in the external periphery of the existing fluid pipe 1, consequently cut off work accuracy in the radial direction of the existing fluid pipe 1 can be improved.