Design and fabrication of FRP vessels under pressure is ruled by ASME Code Section X. ASME is the American Society of Mechanical Engineers. Design and fabrication of FRP vessels at atmospheric pressure is ruled by standard NBS PS15. NBS is the National Bureau of Standards of the United States of America.
On both publications you'll find plenty of information on how to fabricate FRP vessels. Based on that, you'll have to write your own Inspection Procedure. If you're fabricating the vessels for somebody else (a client), the Inspection Procedure will have to be approved by the client before using it. On the other hand, if you're the client and some fabricator is making the vessels for you, it's you who will have to approve his Inspection Procedure.
Giovanni S. Crisi
Sao Paulo - Brazil