Patent ID: 7304267

Claim:
A buttering method of depositing a welding material in an annular facing machined in a concave inside surface of a spherical wall at a periphery of a zone of the spherical wall that is to receive a through tube, the welding material is deposited automatically by performing the following operations: causing a welding torch comprising means for melting and means for feeding welding material to rotate about an axis of rotation; and simultaneously causing the welding torch to move in a direction perpendicular to the axis of rotation in a controlled manner, and adjusting the position of the welding torch in a direction parallel to the axis of rotation in such a manner as to deposit the welding material in the annular facing in the form of at least one elliptical weld having characteristics that are constant; wherein the axis of rotation extends in a direction that is radial relative to the spherical wall and passes through a central point of the annular facing where the inside surface of the spherical wall intersects the axis of the through tube.