ASME Mark for Pressure Relief Devices, Alternative Marking Methods

Starting with the 2011 edition of the ASME Boiler and Pressure Vessel Code, a revised ASME Code certification mark replaced all previous ASME pressure relief device stamps (V, HV, NV, UV, UD, TD stamps). The new ASME certification mark is the same for all Code stamped items, and is accompanied by a “designator” which identifies the specific product. The designator consists of the letters that were part of the previous Code stamp for that product. The new stamp and designator were implemented by the end of 2013. (Note 1)

(XX = “designator” of V, HV, UV, NV, UD, or TD)

The standard stamp for the ASME certification mark which is supplied to ASME Certificate holders is ½” by ½” (12.7 mm x 12.7 mm) which is larger than the previous Code stamps. Additional space is also required for the designator, which is stamped by the certificate holder (no stamp is supplied for the designator). Finding space for the standard stamp and additional designator may be a problem on many pressure relief devices.

An acceptance procedure is available to organizations that wish to use an alternative to the stamp issued by ASME. Alternative methods of applying the certification mark must be accepted by the ASME Designated Organization which is the National Board. [code references: Section I, paragraph PG-110, Section XIII, paragraph 3.9(e)(7), 4.7.2(j), 4.7.3(d), 5.7.2(i)]

The alternative method to be considered must meet the following criteria:

  1. It must be an accurate facsimile of the ASME certification mark. The designator must be centered under the stamp itself.
  2. The size of the stamp is not restricted, but it must be legible and permanent.
  3. The procedure for controlling the use of the alternative stamping method must be documented and addressed in the quality program.

Alternative methods that have been used include: roll stamping with a die, laser marking, photosensitive etching, metal etching or metal dot matrix printing.

To have a proposed method of applying the ASME Certification mark accepted, please provide the following information:

  1. An approved drawing or other method of documenting the dimensions and arrangement of the new stamping. In some cases this may be a CAD or drafting file identification. The drawing or file must be approved and controlled.
  2. A sample of the actual stamping method on a nameplate, tag, valve body, or rupture disk holder shall be supplied for our inspection.
  3. A copy of the proposed procedure for controlling use of the stamp.

This information can be sent to the following address:

National Board Pressure Relief Department
7437 Pingue Drive
Worthington, OH 43085

Email to:

Please call 614.888.8320 and ask for the Pressure Relief Department for more information.


  1. See ASME Code Case N-822-4 for additional information on use of the ASME NV designator.
  2. Please use this procedure for alternative methods for applying the National Board NB mark or VR valve repair stamp.

Updated: 9-6-22