46 CFR §109.573

1. (a)The master or person in charge shall ensure that there is no riveting, welding, or burning—
   1. (1)In a fuel tank;
   2. (2)On the boundary of a fuel tank;
   3. (3)On pipelines, heating coils, pumps, fittings, or other appurtenances connected to fuel tanks; or
   4. (4)On the boundary of spaces adjacent to tanks carrying Grades A, B, or C flammable liquids in bulk.
2. (b)The operations prohibited in paragraph (a) of this section may be allowed if—
   1. (1)An inspection conducted in accordance with the “Standard for the Control of Gas Hazards on Vessels to be Repaired,” N.F.P.A. No. 306-1974, is made—
      1. (i)In ports or navigable waters of the United States, its territories and possessions, by—
         1. (A)A marine chemist certified by the National Fire Protection Association; or
         2. (B)If a certified marine chemist is not available, a person designated by the Officer in Charge, Marine Inspection; or
      2. (ii)In all other locations by—
         1. (A)A marine chemist certified by the National Fire Protection Association;
         2. (B)If a certified marine chemist is not available, a person designated by the Officer in Charge, Marine Inspection; or
         3. (C)If the persons required in paragraphs (b)(1)(ii) (A) and (B) of this section are not available, the master or person in charge; or a welding supervisor designated, in writing, by the master or person in charge; and
   2. (2)A certificate is issued by the person conducting the inspection stating—
      1. (i)That he conducted the inspection in accordance with the standard in paragraph (b)(1) of this section;
      2. (ii)The operations that may be conducted; and
      3. (iii)A list of precautions to be followed during the operations;
3. (c)The master or person in charge shall ensure that the precautions in paragraph (b)(2)(iii) of this section are followed.