Asme?

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I have a couple questions on ASME certs.1. Is SCH 80 used for an unlimited thickness qualification?2. What is the most common vessel cert? (there even is one)Im asking becuase its pretty slow at work right now, and its a goal of mine to become a pressure vessel welder.  Thanks in advance. And yes they do vessels at my shop and i know they dont transfer.6G zirconium 702 GTAW 2" xxheavy6G P.E.D. carbon steel GTAW 2" xxheavy3G titanium Gr. 2 - Gr. 7 GTAW up to 3/4" 3G 316L stainless GTAW up to 1" 3G carbon steel GTAW up to 1" 3G Hastalloy GTAW up to 3/4"1G tantalum GTAW up to .060"
Reply:I was going to answer this for you but I can' find my book with the ASME codes. It has been a few years, quite a few in fact, since I retired so I'm a little fuzzy on this. When I retired I carried an ASME code 9-G6 certification. I'm certain on this. It was on 6" sch. 80 gr. B seamless pipe. It consisted of a downhill stringer with 6010 rod and the rest uphill with 7018 in the 45 degree position. This qualified you for all rods, all positions for any weld up to the low alloy steels. What I'm fuzzy on is the tensile strength of the steel you were allowed to weld on, 70K I think but not sure. When you went to alloy steel you tested on the specific steel you were to weld.You cut four coupons and ground them to the same thickness as the pipe, then radiused the corners. They did two back bends and two side bends, no flaws allowed. Has this changed? I have no idea.
Reply:Originally Posted by welder155I have a couple questions on ASME certs.1. Is SCH 80 used for an unlimited thickness qualification?
Reply:ok thanks cause i was thinking of trying something like 6" sch 80 pipe with a downhill hardwire root and a fluxcore or metalcore uphill fill and cap. (depending on position)essentially cause i mainly weld in the shop not really in the field id like to do wire. so that would be something like a procedure huh?6G zirconium 702 GTAW 2" xxheavy6G P.E.D. carbon steel GTAW 2" xxheavy3G titanium Gr. 2 - Gr. 7 GTAW up to 3/4" 3G 316L stainless GTAW up to 1" 3G carbon steel GTAW up to 1" 3G Hastalloy GTAW up to 3/4"1G tantalum GTAW up to .060"
Reply:Find out what the most common procedure used in your shop is..  and take that one. It will get your foot in the door and possibly get you a shot at more certs.
Reply:ok thats what i was thinking im going to ask him tomorrow.and cause im really interested in this stuff but dont know much about it haha im learning to fit pipe aswell as weld pipe.so are there certs on plate that can qualify to weld pipe because my metalcore test qualifies me in structural as well as pipe 24" and bigger per note 3 so what does all that mean basically i want/need all the pipe info i can get6G zirconium 702 GTAW 2" xxheavy6G P.E.D. carbon steel GTAW 2" xxheavy3G titanium Gr. 2 - Gr. 7 GTAW up to 3/4" 3G 316L stainless GTAW up to 1" 3G carbon steel GTAW up to 1" 3G Hastalloy GTAW up to 3/4"1G tantalum GTAW up to .060"
Reply:ASME Certifications vary from manufacturer to manufacturer. A plate test will allow you to weld on certain size pressure vessels. The needs of the manufacturer will dictate what test is to be taken. A pressure vessel mfg may use FCAW for all of their vessels and all of the vessels are large enough to have access to noth sides of the joint. To weld any seam on that, plate tests suffice. Wouldn't even need to be an open root. As others indicated a common test assembly is a heavy wall pipe or tube coupon with 1/2" wall or greater. If you deposit 1/2" of weld metal in a 1/2" groove you are qualified unlimited thickness PROVIDED you used at least three layers. If the diameter of your coupon is 2-7/8"OD or less (2-1/2" NPS) then you are also qualifed down to 1" OD.They may manufacture pipe nozzles that attach to the vessel. These may be stick welded. You could do a plate test and qualifiy to weld down to anything greater than 2-7/8" OD but only in the flat and horizontal position.The tests that are "ASME TESTS" vary considerably. Tee joint fillet weld tests are given, plate tests, socket weld tests, pipe tests. Rules exist for position, base material type, filler metal, progression etc. Here is a sample WPQ form I made for a plate test with SMAW 6010/7018 . http://weldingdata.com/welder1.jpgAs you can see there are a few variables that come into play for the welder performance qualification.Hope this helpsLast edited by gaustin; 04-07-2008 at 11:24 PM.Have a nice dayhttp://www.weldingdata.com/
Reply:I've only worked with mild steel and always tested to code 9-g6 for pipe, not sure what the structural test was but it was done on 1/2" plate. If you qualified on the pipe the structural certs were automatic. I worked for a time in a code certified heat exchanger shop (heated pressure vessels). To be hired you had to pass the code 9 g6 test on sched 80 6 inch. I would guess it covered me for all mild steel as I never had to take another test. Now alloys were a different matter and each had it's own test. If you are in a code shop they will have all the info on testing for you as they are required to have it on site.The difference between art and craft is the quality of the workmanship. I am an artist.