Patent ID: 8044323

Claim:
An apparatus for improving residual stress of piping, which irradiates an outer surface of a T-piping with a laser beam emitted from a laser head, said T-piping comprising a first piping having one end welded and connected to a tubular circumferential surface of a second piping, and comprising: a circumferential-direction position adjusting structure for moving the laser head along a circumferential direction about a tubular axis of the first piping; a tubular axial-direction position adjusting structure for moving the laser head along a tubular axial direction of the first piping; a radial-direction position adjusting structure for moving the laser head along a radial direction of the first piping; and an emission-direction adjusting structure for changing an emission direction of the laser beam in a plane including the tubular axis of the first piping, by changing a direction of the laser head, wherein the circumferential-direction position adjusting structure includes a rail mounted on a surface of the first piping, wherein the rail includes a ring shape surrounding a periphery of the first piping, wherein the circumferential-direction position adjusting structure further includes a cart traveling on the ring-shaped rail as a track, wherein the radial-direction position adjusting structure includes a guide roller making a rolling contact with a circumferential surface of the first piping, wherein the radial-direction position adjusting structure includes a support portion fixed to one end of the tubular axial-direction position adjusting structure, the support portion extending in the radial direction of the first piping and supporting the guide roller at one end thereof, the one end of the support portion facing the first piping, and wherein the radial-direction position adjusting structure slidingly moves along the radial direction of the first piping, with respect to the support portion.