The dreaded 6g pipe test!!

admin

Ok I have to start learning some pipe for an upcoming high preassure test.I must say you gotta love how work just springs these test on ya.Ok i have never attempted do pipe before so i'm sure i'll mess up quite often before i get it but hey it's not my money...lolAs far as i know it's a 2" pipe open root with a 30 degree bevel, 1/8 gap.My plan was to hit the root with a 1/8 6010 rod and then fill it up and slap a cap on with a 7018.What setting range would you start with for a 6010 in the root?I'm not even sure what the thickness is.Last edited by steve28; 10-02-2006 at 02:05 PM.
Reply:I got a buddy that is a fitter, I would say 120 amps for your root. I'm not sure but I think he said that most of the guys that weld on his jobsites just run a 6010 root, and then 7018 the rest. Now I'm no pipe welder, but I would say get you a piece of 2 inch and practice, practice, practice. ( I can say that the open groove is a bitch though).... Good Luck!!!!Miller blue star 2eLincoln 175
Reply:some how that seems abit hot guess i'll have to do some trial an error!What about technique, is a slight back-step a good idea for the root?
Reply:thats what im working with most of the time and with 6010 and a 1/16 th inch root face and an 1/8th inch root gap i'll run anywhere from 60-75 amps. but general technique is to have your arc even with the backside of the pipe and fill in the keyhole. try it and i think you'll get what i'm talking about. good luck and have fun with it!
Reply:God I wish you guy's would catch up with the rest of the world and go metric 2mm face and butt it up almost tight, and in at 100 or so for me, but you'll have to play yourself and see what suits you. Oh and normally straight polarity is my prefered, but either way does the jobI'd rather be hunting........USE ENOUGH HEAT.......Drifting around Aussie welding more pipe up, for something different.....wanting to get home.
Reply:Steve 28My advice would be get a copy of the AWS ( I presume AWS has the Code) that covers your 6G) It will give the parameters you are required to weld to and assessment criteria.I tested applicants for the much harder AS 1796 certifications and invariably most that failed not because a lack of welding skill, but because they were simply unaware of all the criteria that had to conform to.Parameter examplesCap height to a measurement +- and a height to width ratioWeld bead width no more "x" than the prep widthRoot bead height Max and with no suck back ( suck back is the root run shrinking back under pipe wall thickness )No arc strike outside weld bead areaUndercut set at a minium total length anm max allowed depthNO inclusionsNo, weld stop /start craters.No lack of root fusion defectsOn top of that there was a mechanical cold root bend test and a side break test.I would be surprised if the mechanical test was performed on 2" pipe. Obviously they must be  radiograped.These are examples from the Aussie code. I am not suggesting they are for 6G, but some of them could be.We tested on 6" x 1/2" wall th in the fixed position not rolled. Compared to one fixed  at 45 degrees inclined the 6 g is a piece of cake.Get your info first so you practice to avoid the causes of failure.I hope this was a help to youGrahame
Reply:i guess i can get this info from the QC (quality control) guy at work. from what i hear it's a 2" pipe because it allows you to weld larger pipe not smaller, i could be wrong but this is what i heard!
Reply:if I rememer correctly 2in only allows up to 6in.  I am sure I will be told differently.  If  I'm wrong I am wrong though.
Reply:2 inch sched. 160 = the same qualification as 6 inch shed 80.sugestion: 1/8 land, 1/8 gap, uphill root.root- grind out your "wagon tracks".find out about the hot pass, will they allow a quick down hill pass ? if so jack it  up a bit and give your self some meat to work with. if not I don't grind quite as much cause the 7018 will take care of some imperfactions (really a bunch)if your running hot enough. .-once you get past the root and hot it smooth sailing. #1 one rule, if you don't know what the inspector expects, ASK ! #2, keep it clean#3, relax     good luck, we all go through it         jas  while your practicing do "exploratory surgery", grind all your stops and start to see if there is any porosity. if no then the only thing you should have to grind is your root. porosity at starts and stops means your not running hot enough.hope this helpsend of rambling.......
Reply:ASME: 6G on 2" XXH is good from (approximately) 7/8" dia and up (half the diameter of the pipe), thickness to about 1.25" (the wall thickness of XXH is about 5/8", and you get qualified to twice the thickness of the coupon)Get the details of the test procedure in advance: current, electrode size, other conditions such as fixtures to be used, can you grind (many tests are run no grinding allowed, just a chipping hammer and maybe a file), time limit, acceptance procedure, etc. I would run root and hot pass 6010, fill 7018. Lay the hot pass on as thick and flat as you can do cleanly. Then you can shovel in the '18. The fewer passes and faster you run, the smaller the HAZ. Just be sure to get the fusion. Typical acceptance is less the 1/32 protrusion or suck back at the root, and cap 1/16 over flush with no significant undercut, though this will vary.
Reply:Wish I could see all the other posts when I make a reply....Anyhow..........There's alot of good info in this post, especially from the ones that mention some form of the ASME code.3/32" gap + or - 1/32" is part of the code.A 2" XX will allow you unlimited thickness & I think diameter.Try running the root on straight polarity, a somewhat cold heat setting & don't oscilate the rod, just lay it in there.I once took a 6" heavy wall test to get the job (no grinding allowed) and the test lab said that it was flawless. Hey it worked for me & it was worth $20k for a 4 week job. Once the 6010 root is in just clean up the slag and go right to 7018 to fill and cover. Make sure the 7018 is in some kind of rod oven, hot rod is just better to work with.I could be mistaken but I think the 6010 root pass would qualify for low pressure pipe whereas a tig root would qualify for high pressure.Good luck & let us know how you make out.Tennessee Squire Association
Reply:Originally Posted by mlmonteWish I could see all the other posts when I make a reply....
Reply:Originally Posted by mlmonteWish I could see all the other posts when I make a reply....Anyhow..........There's alot of good info in this post, especially from the ones that mention some form of the ASME code.3/32" gap + or - 1/32" is part of the code.