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Apache Stainless Equipment Corporation


Requirements for the Repair or Alteration of ASME Stainless Pressure Vessels

Whether an accident, environmental damage, or refurbish needs, vessel repair may be necessary at the customer site.  It is important that whoever works on ASME pressure vessels is qualified, certified, and experienced. The National Board, the regulatory commission for ASME, requires an ASME R-Stamp for the repair or alteration of pressure vessels.

Repair areas and welds should be carefully assessed before repair.  Qualified technicians may use die penetrant, x-ray, or ultrasonic devices to inspect welds and surface defects.

If the vessel requires repurposing or refurbishment, qualified ASME engineering professionals must be involved to make sure the changes are compliant with ASME. 

All nozzles and attachments added to the pressure vessel must be ASME compliant.  In addition, there are specific requirements for materials by ASME, including all attachments that are welded to the pressure boundary.

The welding procedure for ASME vessel repair is extensive to include rules for joints, torch cutting, arc gouging, grinding, reinforcement and post weld treatments.

For all repairs or alterations to stainless vessels, it is essential to know the materials and heat treatment requirements. The owner of the vessel, the manufacturer of the vessel, or the National Board (if registered) will have a data report on the vessel which includes a history of all repairs and ASME data for the vessel.

Sufficient time for the proper repair or refurbishment of the vessel is also a requirement.  The tank or vessel needs to be off-line for proper testing, prep, verification, and compliance documentation to be accomplished.  Repair or refurbishment may take a few days to complete, so discuss the plan and process with your repair organization.  Apache provides a realistic timeline estimate after the results of the repair / refurbish assessment. 

Apache Stainless, as a qualified ASME R-Stamp manufacturing organization, will work with the customer, NDE (Non-Destructive Examination) firm (if required) and third-party inspector during the process and will provide the R stamp documentation to the customer and the National Board (NB) when completed.

There are significant requirements for R-stamp approval including:

  • Qualified material documentation
  • Supporting calculations
  • Qualified and certified welder, and welding procedures
  • ASME inspector and witness to R test and attachment of stamp
  • Registering with the National Board.


Apache’s technicians are fully certified ASME welders.  With over 40 years’ experience in vessel manufacturing and continued excellent inspection ratings from ASME auditors, Apache is a solid partner for ASME compliance design, manufacturing, and repair.


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