calling pipewelders if any, need a hand.

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Hey everyone. my name is remo i'm from fountain, SC. i'm in college for welding this is my actual last semister but will be back cause i was ill inform how to do my welding cert in 3 semesters so i have to go back for two speciality clases.(stainless pipe and aluminum)anyway here's what i'm doing within the next several weeks i will be taking a Nuclear power plant test for a job. i know the test is freaking hard. it's being x-rayed. so here's the process.to be hire you need to:1/8 gap, 1/8 filler wirer, Tig root, tig hot pass, 7018 stick filler and cap on a Sch 160 2" pipe in 6G postion.then once hired:1/8 gap, 1/8 filler wirer, Tig all out on a Sch 40 2" pipe in 6G postion.(a freaking handrail.)here's two Sch 160 pipe and one Sch 40 both are 2" I.D.Sch 160 pipe 2" I.D.and Sch 160 tacked and ready to be weld in 6G postion.so what i'm looking for is what to keep and eye out for in sense of porosity or incomplete fusion(which i'm not worry about i run hot) or getting any slag between welds. i think where the problem i will have is the pipe drawing from side to side. since i'm inexperience in correcting this this is where i feel i'll have the problem at. so anything you can help a mofo out would be helpful..thank you remoit's trust and character I need around me. You know, who you choose to be around you lets you know who you are. One car in exchange for knowing what a man's made of? That's a price I can live with. - Hans
Reply:it's that bevel what they want or is it of your own design? are those tig tacks in the last picture??if you want some online input u must provide more pix with root pass finished in&out and cap--------------------------------------------------------------www.becmotors.nlyup, I quit welding.. joined welder anonymous
Reply:Hey remoer,I havent worked at a nuclear plant, but have done extensive work at a coal fired generating station. I have to hold tickets on stainless, 2 1/4 chromoly that require tig roots. By looking at your coupons your bevel angle is way off. I am not sure what this procedure calls for but on any high pressure work ive done it requires a max included angle of 75* or 37.5* per pipe bevel. Your going to acquire alot more distortion with that large of a bevel. As for tacks all you need is (2) tacks on 2" pipe. One at 6:00 and one at 12:00. No more than 1/2" long. I can admit that i dont know how to "walk the cup" i free hand everything so as far as technique im not sure which you are using. Also the word xray is not somthing to be afraid of, if during your root you know for a fact that you've dipped the tungsten or worst case broke a piece off in the weld pool stop immediately and grind that out because that will absolutely be caught on an xray. As for your fill/cap, i know some testers done totally approve of a weave for fill, but i find it almost garuntees zero high spots, peaks, valleys, in which inhibit the chances of trapping slag and create lack of fusion. My procedure for 2 1/4 chromoly requires 400* preheat which is to be maintained, i use a 5/32" gap with 1/8" wire that has been sanded and cleaned, 90 amps for the tig root, then 3/32" 9018-b2 at 86 amps for hotpass, fill, and 84amps for cap.
Reply:Originally Posted by Donoharmit's that bevel what they want or is it of your own design? are those tig tacks in the last picture??if you want some online input u must provide more pix with root pass finished in&out and cap
Reply:Originally Posted by remoernow as for the bevel it's suspose to be 37.5* but our bevel machine are not acurate and it's along the line 37.5* ish..  i.
Reply:RemoIm in Pickens and our banjos play more than yours! Other than that I dont have a clue what you all are talking about so Ill go back under my rock and read.
Reply:I too think your bevels are wrong.Here is a 2 inch sch 80 pipe beveled to 37 1/2° Don’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:It might depend on Cert/Ticket, or WSP. But we always bevel to 37.5 degrees. That looks like waaay more. I didnt pass TIG root with 7018 fill and cap on a 2" sch 180 6G test. My root bends failed. 2 out of 4... waa waa...IN my defense, Im not that well-versed in TIG, so thats my excuse...lolI do remember it took a solid 3 hrs tack to cap test...Lincoln Power MIG 210 MP ( boat anchor )Lincoln Weld-Pac 100 HDHobart IronMan 230Cutmaster 42Jackson NexGenSumner Ultra ClampsDWM120
Reply:unless you are really good set your gap to 5/32 and use 1/8th wire or you may shoot bad for if on your test but on the other hand the test booth is the eaisest place you will ever get to weld
Reply:I have done both these pipe tests with the same materials and pipe specs. The exception is my carbon steel sch 160 was a 6010 root, 7018 fill and cap. Yours should be a piece of cake since you get to put your root in with tig.If you have to use 1/8 filler, I 'd use 1/8 root gap plus a wee bit extra for expansion. I prefer a feathered edge for tig roots. If I use a land with a tig root I never seem to get full penitration. With carbon steel tig root you dont need any back shielding.Allow your pipe to cool before you try to put your cap on. Go have lunch, come back and cap the pipe after it cools. If you try to weld sch 160 all the way out and cap it, you will have problems. Too much heat.For your stainless pipe test, your going to need back shielding. We have to use solar flux where I work. 1/8 filler, 1/8 gap plus a wee bit extra for expansion, Feathered edge, no land....Thats what works for me.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:remoer,The first thing to do is RELAX!  I know, easier said than done, but at least try.  Being uptight will not help in any way.I've tested for the nukes more times than I care to count.  They're just like any other outfit that's got a strict quality control program.  They expect damn near perfection every time and with good reason.  And just as was said, the test booth WILL be the easiest weld you will make.  Wait till you get in a C-zone and get to weld with a full face respirator while twisted around like a pretzel.   Enough of that for now.Find what works for you on your root pass and practice, practice, practice. Make sure that you can weld equally well with either hand.  If not, start practicing now!  Most of the time you will be allowed a choice of 1/32" or 1/8" gap and sometimes a choice of 2, 3 or 4 tacks.  Most common I've found is 1/32"  gap with 4 tacks about 1/4" long at most.  Prep your coupons as instructed to the letter.  Generally, a 1" minimum cleanup, inside and out, from the weld area.  You will be allowed 1/16" reinforcement with no suckback on the root with a minimum flush to 1/8" reinforcement on the cap with NO undercut. These are generalities, what you could be expected to conform to, but may not be the actual requirements.  When you test, they will give you the guidelines to follow.  Listen and do as they tell you!  If you blow by a hold point it will be an automatic failure!Keep your fill passes clean with no tight spots to trap slag.  Know how to start a rod without having porosity and make good tie ins without having a large nob at the bottom.  Use a pipeliner file and a good pick to clean your welds.  A regular half round file will work in place of a pipeliner.  You will probably be allowed to use a grinder and wire wheel, but not guaranteed.  I always take a .045" wafer wheel, an 1/8" grinding rock, a tiger paw and a wire wheel for a 4 1/2" grinder along with a set of nuts to fasten them with and all the tungsten I think I would need to weld a half dozen coupons  along with my own stinger.  Never hurts to be prepared!  Pay attention to your weld puddle and keep the proper rod angles.I can weld out a 2" heavy wall coupon with a 5/8" thick wall in about 2 hours with 3/32" wire and rod, but you will probably be allowed 4 hours.  Practice and then go in that weld booth full of confidence in yourself and your abilities and you will do just fine. Good luck and keep us posted.  Bob."The man of great wealth owes a peculiar obligation to the State, because he derives special advantages from the mere existence of government."  Teddy RooseveltAmerican by birth, Union by choice!  Boilermakers # 60America is a Union.
Reply:One thing that nobody mentioned in case you didn't know.  Absolutely NO arc strikes allowed anywhere on your coupon!  All welding is expected to be done in the weld joint."The man of great wealth owes a peculiar obligation to the State, because he derives special advantages from the mere existence of government."  Teddy RooseveltAmerican by birth, Union by choice!  Boilermakers # 60America is a Union.
Reply:After looking at the pictures of your pipe preparation, may I suggest that you clean the inside of  the pipe to a perfectly clean surface, as you have done on the outside.And what some of the others said: run a few practice welds, get comfortable with your ability, relax, and go run a perfect test coupon!Best of luck...........Bgbkwndo.Last edited by Bgbkwndo; 11-20-2010 at 01:08 AM.Reason: I want to add to my post.
Reply:Originally Posted by Bob the WelderOne thing that nobody mentioned in case you didn't know.  Absolutely NO arc strikes allowed anywhere on your coupon!  All welding is expected to be done in the weld joint.
Reply:Yes, all arc strikes need to be covered by the weld.  You need to be very careful on that 2" Sch. 40 coupon.  It sounds easy enough, but it's not.  Porosity being the culprit.  The permissible porosity per ASME IX, which is what you'll be testing to for nuclear, is 20% of your wall thickness, meaning that you're only looking at .030" permissible.  In other words, if you can see it on film, even if it looks like the width of a pinhead, you're probably out the door.  We've had guys with 300+ good shots on boiler tubes with 0 rejects bust a 2" Sch. 40 in the 2G position for that reason.You can't take the fundamentals for granted.  That means the inside and outside of your coupons should be down to clean, bright metal, your filler kept in the gas envelope at all times during welding, and the end of your filler snipped every time you break your arc.  I'd also suggest running the largest gas lens you're comfortable using.
Reply:Good point on cleaning the coupons. With carbon steel esp, I will take mine to the sand blast cabinet and clean then inside and out in there.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:hey kid stick with what you know! alot of these "welders" have never seen a nuke plant, i have, and everything depends on q.c. just do what you know, bead the coupons then turn up the heat for your hot pass, then fill and cap it....STICK WITH WHAT YOU KNOW!!!! it's only metal, and yes cleanliness is godliness when welding use everything to your advantage
Reply:CEP, Just as I said, absolutely NO arc strikes anywhere out of the weld zone.  Arc strikes are considered to be stress raisers and are not looked upon kindly by weld inspectors for ASME code welds.  They frequently require their own procedure to be written for repairs.  The marks you show on your coupon are considered a defect.  They are a result of improperly cratering out on a tig weld.  It is the result of that uncontrolled spray that leaves what we call pecker tracks. I guarantee that the marks on your coupon are in the steel.  If the inspector doesn't happen by you can touch them up with careful use of a file or tiger paw if they are not outside the 1" cleanup area because they are generally not very deep and can easily be removed."The man of great wealth owes a peculiar obligation to the State, because he derives special advantages from the mere existence of government."  Teddy RooseveltAmerican by birth, Union by choice!  Boilermakers # 60America is a Union.
Reply:Thanks for taking the time to explain that Bob!That picture of the coupon I posted was tacked with 6010, do they really expect you to control the sparks with 6010?Don’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:Yeah, going back and looking closer I see the smoke from stick welding on the edges.  But you can have the same results with pecker tracks from long arcing xx10 types of rod. You have to be very careful to avoid them.  No controlling the spatter from welding, but they will expect your coupons to be free from the pits caused from long arcing."The man of great wealth owes a peculiar obligation to the State, because he derives special advantages from the mere existence of government."  Teddy RooseveltAmerican by birth, Union by choice!  Boilermakers # 60America is a Union.
Reply:Thanks for the information Bob. Good thing I spend my life working under D1.1 code. Sounds a lot easier than ASME codes! Don’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:Heres a few pictures that a tester took while i was doing my yearly high pressure qualification testing. This particular test was 2 1/4% chromoly, tig root and 9018-b2 fill/capJust personal preference i use a 5/32 gap for root, and just a extremely slight landing that i put on with a file. Less than a 1/16th. I freehand my tig roots as i was never taught to walk the cup. Our procedures only require tig roots and we fill/cap with stick always so walking the cup isnt a huge concern of mine as far as speed goes. Attached Images
Reply:very good information by all, I will add my 2c, to help you through this. First i would purge the pipe with a shielding gas even on the carbon steel as it will make the root go alot smootherSecond i would put four tacks so you can break this weld test into four quadrants, makes it easier to weld when you do one section at a timeThird i would make an adjustable jig that you can positon for comfort (i will try to remember to post pictures of the jig i use when i do the ASME test)Forth, when welding relax, it is just another day of welding, i always try to keep the weld parallel to the horizon as i move up the pipe for the stick passes, the tig root i would wash the weld up the sides of the bevel and would have a feather edge as someone posted before, so you get the good penetrationdoing a weave with the weld should not be an issue, just watch the current settings, good luckSteve Hot Rod HooliganMiller Maxstar 200 STRCampbell Housfeld Flux Core 80
Reply:Usually department of labour welding examiners will not allow a purge gas while in a testing situation if it is not nessecary whereas it is for stainless, titanium, inconel etc. The reason for this is that they want to simulate a real life situation in regards to work in the field. You should be more than capable to put in a tig root on mild steel with no problems. Also when it comes to tacking their is a very specific order and amount of tacks needed per pipe during a welding examination. 2" sch 160 requires no more than 2 tacks and in most cases can be no longer than 1/2" in length. 4" pipe requires 3 tacks, etc. This will change and vary when it comes to wall thickness and pipe diameter, wether bridge tacks are required etc. You want to ELIMINATE stop starts during a testing situation. As far as welding jigs for the 6g application, make it as simple as possible. Dont get yourself into making jigs that force bad habbits on you. Things ive seen pertaining to this are... arm rests, moving the stand up/down to make pass's easier during test. A good welder can adapt to any situation that arises, in order to better yourself you have to challenge yourself. Hooligan* i am not trying to shoot down your practices, im just explaining how strict guidelines are when it comes to testing.
Reply:gentlmen thank you very, very much for the help. well it seems the job has been put on hold for several reasons. "from hearsay" i can't verified it but. it seems it was put on hold due to trying to get some paper work staright, also there are really two test and most ppl can only pass one, not the second and of course there's always rumors. and hoo i went and started practicing other thing today.practicing back gouging on 3G open butt plate Flux-core. here's me practing the gouging before i actually gouge the plate. then went to the pipe rack and welded a 5G 6" pipe. 6" off the plateform. let me say that was hard, the confined space, more one cutting my rods and making it work.. again thank everyone for the advice and help.it's trust and character I need around me. You know, who you choose to be around you lets you know who you are. One car in exchange for knowing what a man's made of? That's a price I can live with. - HansOriginally Posted by Pressure_WelderUsually department of labour welding examiners will not allow a purge gas while in a testing situation if it is not nessecary whereas it is for stainless, titanium, inconel etc. The reason for this is that they want to simulate a real life situation in regards to work in the field. You should be more than capable to put in a tig root on mild steel with no problems. Also when it comes to tacking their is a very specific order and amount of tacks needed per pipe during a welding examination. 2" sch 160 requires no more than 2 tacks and in most cases can be no longer than 1/2" in length. 4" pipe requires 3 tacks, etc. This will change and vary when it comes to wall thickness and pipe diameter, wether bridge tacks are required etc. You want to ELIMINATE stop starts during a testing situation. As far as welding jigs for the 6g application, make it as simple as possible. Dont get yourself into making jigs that force bad habbits on you. Things ive seen pertaining to this are... arm rests, moving the stand up/down to make pass's easier during test. A good welder can adapt to any situation that arises, in order to better yourself you have to challenge yourself. Hooligan* i am not trying to shoot down your practices, im just explaining how strict guidelines are when it comes to testing.