46 CFR §50.30-10

1. (a)Classes I, I-L and II-L pressure vessels must be subject to shop inspection at the plant where they are being fabricated, or when determined necessary by the Officer in Charge, Marine Inspection.
2. (b)The manufacturer must submit Class I, I-L and II-L pressure vessels, as defined in parts 54 and 56 of this subchapter for shop inspection at such stages of fabrication as may be requested by the Officer in Charge, Marine Inspection.