We design and manufacture pressure vessels and Air receivers to our clients requirements with marine design appraisal documentation MDAD . this document comes as part of the approval from our Lloyds class pressure vessels. The pressure vessel design calculations and drawing is surveyed by Lloyds marine in London and the approval document is produced as part of that class approval.
A machinery design appraisal document MDMD applies generally to machinery whereas the marine design appraisal document comes complete with a full vessel survey and certification (pressure test and design approval)
Det Norsk Veritas (DNV) and American bureau of shipping (ABS) can also provide design approval for pressure vessels in a marine environment- we work with these companies and others for pressure vessels for these applications to get marine design approval.