Repair of steel pipe.

(a)Each imperfection or damage that impairs the serviceability of a length of steel pipe must be repaired or removed. If a repair is made by grinding, the remaining wall thickness must at least be equal to either:#

(1)The minimum thickness required by the tolerances in the specification to which the pipe was manufactured; or#

(2)The nominal wall thickness required for the design pressure of the pipeline.#

(b)Each of the following dents must be removed from steel pipe to be operated at a pressure that produces a hoop stress of 20 percent, or more, of SMYS, unless the dent is repaired by a method that reliable engineering tests and analyses show can permanently restore the serviceability of the pipe:#

(1)A dent that contains a stress concentrator such as a scratch, gouge, groove, or arc burn.#

(2)A dent that affects the longitudinal weld or a circumferential weld.#

(3)In pipe to be operated at a pressure that produces a hoop stress of 40 percent or more of SMYS, a dent that has a depth of:#

(i)More than 1/4 inch (6.4 millimeters) in pipe 12 3/4 inches (324 millimeters) or less in outer diameter; or#

(ii)More than 2 percent of the nominal pipe diameter in pipe over 12 3/4 inches (324 millimeters) in outer diameter.#

For the purpose of this section a “dent” is a depression that produces a gross disturbance in the curvature of the pipe wall without reducing the pipe-wall thickness. The depth of a dent is measured as the gap between the lowest point of the dent and a prolongation of the original contour of the pipe.#

(c)Each arc burn on steel pipe to be operated at a pressure that produces a hoop stress of 40 percent, or more, of SMYS must be repaired or removed. If a repair is made by grinding, the arc burn must be completely removed and the remaining wall thickness must be at least equal to either:#

(1)The minimum wall thickness required by the tolerances in the specification to which the pipe was manufactured; or#

(2)The nominal wall thickness required for the design pressure of the pipeline.#

(d)A gouge, groove, arc burn, or dent may not be repaired by insert patching or by pounding out.#

(e)Each gouge, groove, arc burn, or dent that is removed from a length of pipe must be removed by cutting out the damaged portion as a cylinder.#