The National Board of Boiler and Pressure Vessel Inspectors (NBBI) created the National Board Inspection Code (NBIC) in 1946, which serves as one of the primary tools for compliance assurance. This code has been adopted by most states and cities in the United States, all Canadian provinces and someUS regulatory agencies, including the US Department of Transportation. It is the only code recognized worldwide for the in-service inspection of repairs and alterations of boilers and pressure vessels (BPV).
VRStamp - The National Board offers theCertificate of AuthorizationandRsymbol stamp for the repair pressure relief valves. The requirements the supplier must meet to be authorized are described in NBIC standards for Repairs and Alterations - NBBI NB-23 PART 3, Section 1.