49 CFR 192.715
Transmission lines: Permanent field repair of welds.
Each weld that is unacceptable under § 192.241(c) must be repaired as follows:#
(a)If it is feasible to take the segment of transmission line out of service, the weld must be repaired in accordance with the applicable requirements of § 192.245.#
(b)A weld may be repaired in accordance with § 192.245 while the segment of transmission line is in service if:#
(1)The weld is not leaking;#
(2)The pressure in the segment is reduced so that it does not produce a stress that is more than 20 percent of the SMYS of the pipe; and#
(3)Grinding of the defective area can be limited so that at least 1/8-inch (3.2 millimeters) thickness in the pipe weld remains.#
(c)A defective weld which cannot be repaired in accordance with paragraph (a) or (b) of this section must be repaired by installing a full encirclement welded split sleeve of appropriate design.#