46 CFR §164.019-9

1. (a)The manufacturer shall not change the design, material, manufacturing process, or construction of a non-standard component unless it has been previously approved by the Commandant, in accordance with paragraph (b) of this section.
2. (b)The manufacturer or the recognized laboratory that performs the acceptance testing required by the applicable subpart of this part or part 160 of this chapter shall submit requests for acceptance of revisions in design, material, manufacturing process, or construction of a non-standard component in writing and describe the revision in detail similar to the original request for acceptance.