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Posts Tagged ‘Nozzle Welding’

It wasn’t too long ago that I walked onto a refinery job site that Precision Pipe was supply equipment to.  At this site I saw an interesting event about to transpire.  A welder who was not associated with our company was getting ready to light a torch next to a vessel we had just delivered the day before. It appeared to me that he intended to cut into the vessel. Surprised to be seeing this, I quickly made my way over to him to see what he was doing.  He informed me that the construction manager (from a well respected and large engineering firm) instructed him to make a modification to the pressure vessel as a solution to a piping problem.  I asked him to stand by for a second so that we could discuss with plant manger the implications his modifications might have.

The welder became rather irritated with me and informed me he had his directions and he intended to follow them.  For those of you that are unfamiliar with the ASME code, let me explain the implications of this kind of modification in the ASME code world. First, if the welder had actually brought his torch to the shell of the vessel he would have undone the ASME certification on that vessel.  In other words the vessel would have no longer been a certified ASME pressure vessel and the customer would have wasted several thousands of dollars on that pressure vessel.  As the manufacturer I would have been required to remove the name plate from that vessel the moment I saw the flame come into contact with it. Second, that vessel would have no longer been acceptable to use on the job site as it was being implemented at a refinery in an ASME mandatory site and State.  Lastly, Precision would have likely had to of retaken possession of that vessel, repair it according to ASME standards, re-certify and qualify the vessel as meeting the ASME code.  The vessel would have also required a second name plate identifying it as an “R” or “Repaired” pressure vessel.

The reality of the situation was, the construction manager was under immense pressure to complete the project and at that point he was willing to cut corners.  What he didn’t anticipate was getting caught in a major blunder which would have added greater delays and expense to his project.  Anything worth doing is worth doing right and this is especially true for engineered products like ASME vessels. Knowing what the proper proceeders are for welding and modifying an ASME pressure vessel is imperative.  In this situation, the only way to modify the vessel is following the ASME code by using a qualified ASME shop with an “R” stamp.  Any welding or cutting on an ASME pressure vessel must be performed by a qualified shop that is in good standing with the National Board.  The pressure vessel will have to be reinspected by a third party authorized inspector and may need to have X-ray and hydrostatic testing to keep the ASME certification and name plate.

As an ASME qualified shop we encourage anyone to use us or another code shop as a resource to answer any question you may have on qualifications, modifications, and inspection of ASME pressure vessels, Heat Exchanger, or Boiler’s.  We would rather take a few minutes to understand and explain what your options are according to the code then risk an accident or injury .  In addition, if we can simply answer your question this a a free service we offer to any prospective customer.  If you are a plant manager and you are unsure if you can use any certified welder?  Give us a call and we can walk you though what it takes to maintain your ASME certifications.  If you have an ASME pressure vessel, Heat Exchanger, or Boiler that needs work or an addition of a nozzle or coupling.  Call us we can tell you what you must do to add the new components in a safe and code qualified manner.

As it turns out I was able to get the welder to wait a minute.  Explaining to him the consequences of his modification calmed him down long enough to bring in the decision makers.  The plant manager, the construction manager (having tucked his tail between his legs), and I all discussed the changes that were necessary and it was ultimately decided a ‘T’ in the process piping was the most effective work around for the problem.  Having an ASME specialist onsite that day saved thousands of dollars, countless hours, and potentially the integrity of the plants operational safety in the future.  Don’t be shy to email or call us or any other ASME qualified shop to discuss your project or equipment with ASME name plates. Your local rig welder or fabrication shop may be good, they may be able, they may even have a piece of paper that  say’s they are certified to make a weld. However, it is imperative you at least speak with a shop that is ASME qualified before you make any welds on a certified ASME pressure vessel.

http://www.Precision-Pipe.com

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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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