Full Pen Welding & Inspection is now U-Stamp certified for Fabrication of Pressure Vessels. The ASME "U" stamp is certification of an unfired pressure vessel built to Section VIII of the ASME Code. This means that a pressure vessel was specified, designed, fabricated, inspected and tested in accordance with this code. A plate with an ASME vessel number is attached to the component. An independent inspector must certify each and every vessel.