Buying Separators & Vessels

  We are frequently asked what "ASME" means and why it is important for a pressure vessel to have a "U" stamp.  Simply put, an ASME U stamp (and its accompanying U1A data form) show the pressure vessel was built according to the standards and specifications defined by the American Society of Mechanical Engineers (ASME).  More importantly it indicates the vessel was inspected by a qualified and certified ASME inpector before being approved and stamped.

Not all vessels are ASME coded and may not comply with ASME standards and should be avoided. Vessels that are missing their tags, whether lost or removed, should also be avoided. Here is a quick breakdown of the most common ASME stamps:

 
Vessel was manufactured following the standards set forth for Section VIII Division 1 by the American Society of Mechanical Engineers. For vessels up to 3,000# psi. For further info see http://www.absa.ca/faq/SectionVIIIcomparison.pdf.

  Vessel was manufactured following the alternative standards set forth for Section VIII Division 2, by the American Society of Mechanical Engineers. For further info see http://www.absa.ca/faq/SectionVIIIcomparison.pdf

  Vessel was manufactured following the standards for high pressure vessels set forth for Section VIII Division 3, by the American Society of Mechanical Engineers. Typically for vessels rated 10,000# psi or higher. For further info see http://www.absa.ca/faq/SectionVIIIcomparison.pdf

In addition to applicable ASME stamps, many vessels have a National Board number. The number indicates the vessel was registered with the National Board of Boiler and Pressure Vessel Inspectors by the manufacturer. Registrations means a report, commonly called a “U1A”, can be obtained at a nominal cost for review before purchase.

   Like the American Society of Mechanical Engineers, the National Board issues vessel stamps. The most common one seen is the “R” stamp and indicates the vessel was repaired or altered according to the standards set forth by National Board of Boiler and Pressure Vessel Inspectors.


When shopping for a pressure vessel like a separator, look for a picture of the original manufacturer’s tag. At a minimum the tag should show:
  • Maximum working pressure and working temperature
  • Year of Manufacture
  • Name of Manufacturer
  • National Board number or drawing number (if available)
  • Any ASME and National Board stamps
  • Additional stamped certifications such as HT (Heat Treated) or RT-1 (Radiological Testing, level 1)

For more information about ASME, visit their web site: www.asme.org.  For additional information, and to find the location of ASME certified shops in your area, visit the National Board of Boiler and Pressure Vessel Inspectors web site at www.nationalboard.org.

 

 
HOME | ABOUT US | CONTACT US | FLARESTACK FAQ | SAND TRAP FAQ | SHRINKAGE TESTER FAQ | TEST SEPARATOR FAQ

(C) Copyright 2011, Mountain Equipment of New Mexic, Inc.  All Rights Reserved.