Delta Certifications Copyright © Delta Fabricating 2011-2012 All rights reserved "NB" Certificate of Authorization from The National Board of Boiler & Pressure Vessel Inspectors  "R" Certificate of Authorization from The National Board of Boiler & Pressure Vessel Inspectors "U" Certificate of Authorization from The American Society of Mechanical Engineers (ASME) "UM" Certificate of Authorization from The American Society of Mechanical Engineers (ASME)