Do you know vessel manufacturers produce Production Impact Test Weld Coupons? Production impact testing is fairly common for vessels with shell walls greater than 1.5” in thickness. Production impact testing ensures that the actual production materials, including weld metal, have the proper toughness requirements to meet ASME Code and applicable specifications that apply to your job.

  • The rules for production impact testing can be found in ASME Section VIII, UG-84 (i). Below are just a few of the requirements that have to be followed before and during the production impact testing welding process.
  • The vessel impact test plate shall be from one of the heats of steel used for the vessel or group of vessels
  • For Category A joints (longitudinal seams), the test plate shall, where practicable, be welded as an extension to the end of a production joint so that the test plate weldment will represent as nearly as practicable the quality and type of welding in the vessel joint.
  • For Category B joints (girth seams) that are welded using a different welding procedure than used on Category A joints, a test plate shall be welded under the production welding conditions used for the vessel, using the same type of equipment and at the same location and using the same procedures as used for the joint, and it shall be welded concurrently with the production welds or as close to the start of production welding as practicable.

The attached pictures in this newsletter are actual examples of what a production impact test plate can look like. In these examples, the test plate is of the same heat as the vessel. The joint design of the test plate matches the joint design of the vessel long seam. The welder or welding operator will start welding the long seam, and as an extension of the long seam, the welder or welding operator will weld the test plate with the same WPS and welding consumables used for the production joint. Once the joint and the test plate are welded, the test plate is Charpy V notched tested for toughness. The condition of the test plate (PWHT, MDMT, mechanical requirements), should be the same as the vessel requirements.

Production Impact Test Test Plate Welding

Question: What if my vessel requires production impact testing, but my company isn’t rolling and welding the long seams? What if we are buying our shells rolled and welded from another company?

Answer: In this case, you need to make sure that the company that is performing the welding on the long seams is aware that the vessel requires production impact testing. They will be responsible for performing the production impact testing for the long seams that they are welding. They will need to supply you with all of the applicable testing reports. Once you are ready to start welding the girth seams, you will also need to run a production impact test with the WPS you are using for production welding.

Long Seam Welding

Question: How do I know if my weld metal will meet the toughness requirements at the test temperature and for the MDMT of the vessel?

Answer: You should always check the manufacturer’s recommendations and certificate of conformance or the MTR’s for the welding consumables. You can also check the classification of the welding consumable in the appropriate specification in ASME Section II Part C. Make sure that the welding consumables used in production meet the requirements of the production vessel.

MDMT of Vessel


We are excited to be able to be hosting our 6th annual engineering seminar on April 19-20. We are excited about the 22 customers coming to Boardman for this course. It’s a great opportunity to learn more about ASME Section VIII Div I code, and fabrication, and have an opportunity to weld and network with other engineers around the country. During our next quarterly newsletter, we’ll share some of the feedback from our 2022 seminar. If you are interested in attending our 2023 course, please let us know.

“The experience that Boardman and the instructor bring to the classroom is incredibly valuable. This course was worth every second of my time and I will be recommending it to all of my colleagues.”
Boardman Engineering Seminar


We have appreciated the positive feedback on the newsletter we’ve sent out over the years. We want to continue building strong relationships with our customers and be a resource as the experts in pressure vessel fabrication. We hope you find this newsletter beneficial as we share tips on the pressure vessel design and construction process. If there are any topics you would like us to address, please let us know!


We would love to hear from you and have an opportunity to quote your next project!

Boardman, LLC

1135 S McKinley OKC, OK 73108


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