Replacing Missing or Illegible Nameplates


Occasionally, nameplates on ammonia refrigeration vessels become illegible or detached altogether.

Does this mean the vessel must be replaced?

Can a replacement nameplate be installed?

If I have a photo of the old nameplate, is that sufficient?

Do I need to contact a regulatory agency?

These are just some of the questions that you may have pondered when dealing with a missing nameplate. As we’ve written about previously, all codes and standards governing the design, installation, and inspection of ammonia refrigeration systems require pressure vessels to be equipped with legible nameplates. The paragraphs that follow summarize steps that can be taken when a vessel nameplate becomes illegible or missing.

Situation 1 – Nameplate is missing, but traceability to the original nameplate is available

If a nameplate is missing, but the owner has evidence of the nameplate information via the manufacturer data report (U-1 or U-1A form) or a photo of the nameplate before it was lost, a replacement nameplate may be installed. Form NB-136 should be completed and submitted to AHJ[1]. In California, CalOSHA Pressure Vessel Unit is the AHJ. The installation of the new nameplate must be witnessed by a National Board Commissioned Inspector[2].

Situation 2 – Nameplate is missing, and the original nameplate information is unknown

If a nameplate is missing and the owner is unable to trace the original information, the AHJ must be contacted to determine the proper steps to take[3]. Unfortunately, there will be no easy path toward obtaining a nameplate and the owner will likely be stuck facing two costly options: 1) Positive material identification and testing to re-rate the vessel and obtain a new nameplate; or 2) Replacement of the vessel.

Situation 3 – Nameplate is partially removed or becoming illegible

If a nameplate has becoming partially detached or is partially illegible, no special permission is needed to reattach the detached portions[4] or to clean the nameplate as needed to improve legibility.

Situation 4 – Nameplate is installed, but cannot be made legible

If a nameplate is installed but has become illegible (as shown in the picture above), attempts should be made to clean the nameplate to gain legibility (as described in Situation 3). If the attempt to clean the nameplate is unsuccessful, then the nameplate should be considered missing and Situations 1 or 2 applied, as appropriate.

Situation 5 – Vessel is equipped with duplicate nameplates and one has become detached

Upon special request, a vessel can be manufactured with duplicate nameplates. If this is the case, and one nameplate becomes illegible, the owner need not take any action so long as the second nameplate can be deciphered. A duplicate nameplate may be reapplied without meeting all of the requirements listed above, but the National Board requests that the original manufacturer be contacted for guidance and direction[5].

For more information on this topic, you can refer to National Board Inspection Code Part 2 Inspection §5 and RETA Book 3 Chapter 5, Page 5-11

[1] 2017 National Board Inspection Code Part 2 Inspection §5.2.2(a) When the stamping on a pressure-retaining item becomes indistinct or the nameplate is lost, illegible, or detached, but traceability to the original pressure-retaining item is still possible, the Inspector shall instruct the owner or user to have the nameplate or stamped data replaced. All re-stamping shall be done in accordance with the original code of construction, except as modified herein. Requests for permission to re-stamp data or replace nameplates shall be made to the Jurisdiction in which the nameplate or stamping is reapplied. Application shall be made on the Replacement of Stamped Data Form, NB-136 (see NBIC Part 2, 5.3.2). Proof of traceability to the original nameplate or stamping and other such data, as is available, shall be furnished with the request.

[2] 2017 National Board Inspection Code Part 2 Inspection §5.2.2(a) The re-stamping or replacement of data shall be witnessed by a National Board Commissioned Inspector.

[3] 2017 National Board Inspection Code Part 2 Inspection §5.2.2(a) When traceability cannot be established, the Jurisdiction shall be contacted for approval prior to replacing a nameplate or re-applying a stamping.

[4] 2017 National Board Inspection Code Part 2 Inspection §5.2.2(a) Permission from the Jurisdiction is not required for the reattachment of nameplates that are partially attached

[5] 2017 National Board Inspection Code Part 2 Inspection §5.2.4 Replacement or re-attachment of duplicate nameplates is exempt from meeting the requirements above provided the information on the nameplate is identical to the original data existing on the pressure-retaining item. The duplicate nameplate shall be marked duplicate. The jurisdiction where the pressure-retaining item is located and the original manufacturer of the item shall be contacted for additional guidance and direction.

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