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Last month I went to an AWS meeting and had a very interesting conversation with a rig welder who owned his own business. We were discussing the work available in the Colorado region and he mentioned that he was doing some repairs on pressure vessels. Curiously I asked if he had a current R stamp or if the company he was working for had a current R stamp. He replied, “I’m just working on some nozzles so they told me I don’t need an R Stamp”. This caught me by surprise. I had understood that any weld on a pressure vessel was part of the ASME code boundary and would require a procedure along with several other items to be approved by an Authorized Inspector prior to work beginning. Not wanting to sound foolish I decided to hold my tongue and do some research within ASME Section VIII, Division 1. Although my definition was somewhat simplified the mind set was correct. Here’s an excerpt from the 2007 edition/2009b addenda of the code:

“U-1(e) In relation to geometry of pressure containing parts, the scope of this Division shall include the following:

U-1(e)(1) where external piping; other pressure vessels including heat exchangers; or mechanical devices, such as pumps, mixers, or compressors, are to be connected to the vessel:

(a) the welding end connection for the first circumferential joint for welded connections [see UW-13(h);

(b) the first threaded joint for screwed connections;

(c) the face of the first flange for bolted, flanged connections;

(d) the first sealing surface for proprietary connections or fitting;”

The list goes on and for the sake of losing whoever might be reading this I’ll leave it to the reader to look up the rest. Let me summarize U-1(e): The code boundary includes any weld joining a nozzle to the main vessel body, the coupling for threaded connections, the weld connecting a weld neck flange AND the flange connected to the piping connected to the main vessel body. Further in U-1(e) the blind flanges or “pressure retaining covers” are also included in the code boundary. Does this impact the way work is performed on vessels here at Precision Pipe & Vessel, LLC? No. We have a current R Stamp issued by the Nation Board of Boiler & Pressure Vessel Inspectors. But for those of you welders and welding companies that are working on ASME certified and registered pressure vessels without an R Stamp I would recommend you stop until you get one. You are accepting the liability of the pressure vessel repair without a qualified Quality System and are by-passing the systems put in place to protect the public from catastrophic failures. If you have a minute check out the 2004 reference on the US Chemical Safety Board website (there’s a link at the end of this blog). The ASME (American Society of Mechanical Engineers) and the NBIC (National Board Inspection Code) codes were written in response to failures of boilers and pressure vessels over the years. They are for the safety of the public. Beware of people and businesses that go around the proper steps of repairing boilers and pressure vessels.

http://www.csb.gov/newsroom/detail.aspx?nid=293

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