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I have a few questions about what to expect in the field when welding pipe.In my last months in welding school, I'd like to work as if I'm in the field, so I'm ready for it.The following questions try to cover everything I can think of. I'm assuming TIG is used for the root and hot/filler pass and 7018 to fill it out the rest if the way and cap.The pipe:What size pipe is the norm?How is the joint prepped? (angle, gap, smoothness of the joint face)How many tack welds and how long are they?TIG set-up:What tungsten size and cup size do you use for the root?What angle do you grind your tungsten tip to?Do you put a flat tip on the tungsten? What size?How much stick-out do you use?Gas lens, ever?What gas mix do you normally use?What is your flow set at?What amperage do you use?What size filler rod?Do you sand off the protective coating on the filler rod?The root weld:Do you use a purge system to protect the root?What pattern do you use to complete the root? (start position, second quarter, ect.)Do you grind out your tacks as you go?How much build-up on the inside of the pipe? (how much is too much?)What does the outer side of the root look like? (wet in flat?, kinda wet in?)The hot pass:What amperage do you use?How far do you weld before you wait for the pipe to cool?Quantity/Speed:How many full joints do you do a day? (and how long is your day?)Do you have a fitter, or do your own fitting?Last question,What industry are you doing these welds for?Thanks in advance, I know I'm asking a lot here.Your answers will help me set up and practice as if I were in a real-world situation. That way, when I get out of school, I'm not just another dip-$#!+ that's fresh out of school. At least I'll have half a clue.
Reply:If you are in a welding school can't you ask your instructor any of these questions?Just wondering.All of these questions will be taught to you in your welding school.You should be doing your tests in school before you go out in the field.It is a lot of territory to cover. From beginning to end is practically a whole welding course.Good questions though.One question did catch my attention."Do you sand off the protective coating on the filler rod?"The coating on the welding electrode is a flux coating that makes a gas when burned thatKeeps oxygen away from the weld. There are different types of flux coatings. Do not sand it off. This will all be explained to you in your beginning welding class.Last edited by Donald Branscom; 03-06-2011 at 03:11 PM.AWS certified welding inspectorAWS certified welder
Reply:Don, sometimes on the weekends we have questions with no instructor around to answer. We ask hoping someone with ~44 years of experience might help us out. Teachers don't know everything and it's always good to ask different people questions to better formulate our opinions/actions. Sorry I can't help you Squid. I'm just a second month student myself . Good Luck
Reply:Originally Posted by Donald BranscomIf you are in a welding school can't you ask your instructor any of these questions?Just wondering.All of these questions will be taught to you in your welding school.You should be doing your tests in school before you go out in the field.
Reply:I'm not a pipe welder by trade, (union thing). I'd say while you are still in school start practicing with the pipe as close to the floor, and wall as you can. Not so hard to weld pipe at the bench. Use a restriction ring, work with a mirror. Pipe welders in the field get everything thrown at them.TIG set-up: Everybody has their own way, I like 3/32 inch ceriated tungsten sharpened to a very sharp point, for the root pass I walk the cup so I use a # 5 cup with a bevel ground on the cup, for a joint prep of 37 1/2 degrees, knife edge, 3/32 inch gap, with 1/8 inch filler. Anywhere from 85 amps to 100 amps, for the hot pass I switch to 3/32 inch filler, and only turn the amps up 5 to prevent suck back. I use a gas lens, with about 15 to 18 cfh. Attached ImagesDont pay any attention to meIm just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:Originally Posted by Donald BranscomOne question did catch my attention."Do you sand off the protective coating on the filler rod?"The coating on the welding electrode is a flux coating that makes a gas when burned thatKeeps oxygen away from the weld. There are different types of flux coatings. Do not sand it off. This will all be explained to you in your beginning welding class.
Reply:I think Don might have assumed that I was a second day student with that reply
Reply:Sorry Donald didnt notice someone got you earlier for the fluxElectricsquid. To answer some of your questions I do some 3" sched 40 or 80 from time to time.grinder finish to a 37.5 degree bevel to a knife edgethink its 22.5 degrees on the sharpener. 3/32 tung. 3/32" gap 1/8" filler or if the gap tightens up i goto 3/32 filler.argon 15CFH @ 82 amps (ish)i like 3 1/2" long tacs 60clock, 10 oclock and 2 oclock. (3 helps stop the gap tighten up)i grind the edges as soon as im done putting them in. (1/16" wheel)No purge for steel.i start on the 6 0clock tack and work up to the next tack. then i go up the other side to the upper tack.I dont walk the cup on the root.i usually get it flush on the inside or slightly convex unless i forget to turn it down from the last cap!!Convex on the outside also, but no undercut.hot pass at 90A (ish) might walk the cup here or freehand it depends on how i feel.then i finish with 3/32" 7018 at 85- 90 (guessing) for a fill / cap depending on the thickness of pipe.I allow 1 hour per joint for 3" sched 80. and hope to do it in less. That includes fitting and tacking it up . Probably some guys here that do it in a lot less..Ill also hop around from joint to joint to cool things down. especially before the cap.the pipe is usually for a main propane gas line in a bulding. they cant tread anything over 2" in MA. the pipe is pressure tested to 5 or 10 psi and runs at @ 2psi when in use.G
Reply:Sorry about the confusion on the coating on the TIG filler wire, as opposed to the coating on the filler rod. Was not being condescending.Answer is the same. Filler wire does not need to be sanded.AWS certified welding inspectorAWS certified welder
Reply:There are as many types, sizes, and schedules of pipe and tube as there are applications for them. Whatever facet of welding you get into will determine the type, size, and schedule you will encounter most often.See what I did there? Now apply it to the rest of your questions... Inevitably, you are going to do it "wrong" when you first get on the job no matter how hard you prepare. Every company, every crew, and every welder has their own way of doing things. Filling your head with too much random junk now ain't gonna help you. In fact, the more "junk" you think you know, the harder, and more frustrating it will be for your superiors to "unlearn" you, and get you to do it their way. Right now, you should concentrate on figuring out what works for you in the different situations presented to you in school, and laying as much wire as you can get your hands on.Buuut, I guess it is a good idea to see who does what, and how. Just don't count on it being the "right way" when you get there is the point I'm trying to get across.Strive to be a good welder under all circumstances, be helpful, and learn everything you can. A good welder... a good ANYTHING never stops learning. It's when you think you know it all, that you trip and fall.And always strive to do more with less. But not your heat! lol. Turn that sh*t up!...I've stopped trying to predict what I will find when I get to a job, there's always a surprise of some sort. Might as well be surprised and pull off a miracle, then plan for the wrong surprise. (That doesn't make ANY sense, but it's working so far!)I never know who or how my joints will be fitted, or if they will be fitted for me at all. Usually (hopefully) not.I never know what kind of equipment I will have or won't have. They call, I go, and I do the best I can with the tools at hand unless it is absolutely, positively not gonna happen without "x, y, and z."
Reply:Originally Posted by ncfhThere are as many types, sizes, and schedules of pipe and tube as there are applications for them. Whatever facet of welding you get into will determine the type, size, and schedule you will encounter most often.See what I did there? Now apply it to the rest of your questions... Inevitably, you are going to do it "wrong" when you first get on the job no matter how hard you prepare. Every company, every crew, and every welder has their own way of doing things. Filling your head with too much random junk now ain't gonna help you. In fact, the more "junk" you think you know, the harder, and more frustrating it will be for your superiors to "unlearn" you, and get you to do it their way. Right now, you should concentrate on figuring out what works for you in the different situations presented to you in school, and laying as much wire as you can get your hands on.Buuut, I guess it is a good idea to see who does what, and how. Just don't count on it being the "right way" when you get there is the point I'm trying to get across.Strive to be a good welder under all circumstances, be helpful, and learn everything you can. A good welder... a good ANYTHING never stops learning. It's when you think you know it all, that you trip and fall.And always strive to do more with less. But not your heat! lol. Turn that sh*t up!...I've stopped trying to predict what I will find when I get to a job, there's always a surprise of some sort. Might as well be surprised and pull off a miracle, then plan for the wrong surprise. (That doesn't make ANY sense, but it's working so far!)I never know who or how my joints will be fitted, or if they will be fitted for me at all. Usually (hopefully) not.I never know what kind of equipment I will have or won't have. They call, I go, and I do the best I can with the tools at hand unless it is absolutely, positively not gonna happen without "x, y, and z."
Reply:I'm quite aware that I'll likely face a wide spectrum of ways employers will expect me to perform my job, depending on the employer and application. So I'd like to get past that and get to some of the details of what others doing. That way I can practice a few different ways while I'm still in school and have the time to experiment. Ultimately, this WILL make me a more flexible welder.Thank you gordfraser and CEP for taking the time to post details about how you set-up and weld your roots
Reply:if thers one thing i can say that i've learned over the past twenty years that i can give advice on is learn to weld your root with varible gaps any were from 3/32 to a 3/16 i have taken weld test for southern co were they wanted a loose1/8 then i've tested on a santee cooper power job were they wanted a 3/16 root opening this is one of the biggest varibles that i can think of .don't be mad cause i can be mad cause you can't!
Reply:I'll try to help, I'n new to the field.. But will relay what i'm doing / experienced. Originally Posted by ElectricSquidI have a few questions about what to expect in the field when welding pipe.In my last months in welding school, I'd like to work as if I'm in the field, so I'm ready for it.The following questions try to cover everything I can think of. I'm assuming TIG is used for the root and hot/filler pass and 7018 to fill it out the rest if the way and cap.Depends on the company and the welding procedure they'll be implementing.You want to be able to tig it out as well as run 7018 out.I've seen both. I'd suggest getting a stainless cert as well if possible.The pipe:What size pipe is the norm? How is the joint prepped? (angle, gap, smoothness of the joint face)How many tack welds and how long are they?Pipe size is all over the place. If your practicing on 2" you'll be good to go.Prepped w/ 37.5 bevel, 3/32nd gap if possible and root w/ 1/8th wire.I always do four tack welds so it minimizes the shifting, distortion.Tack Length varies according to pipe size for me. say 1/4 to 3/8ths is usually sufficient.I like a good tack and you can use it to hit that 6 oclock posistion is a pinch.TIG set-up:What tungsten size and cup size do you use for the root? 1/8th diameter tungsten holds the heat better IMO, 5 or 6 cup for root. Can Walk the root in, or freehand it by dragging the tungsten along/ontop of wire. What angle do you grind your tungsten tip to?I grind it sharp enough to go through anything is accidently touches...Sharp as hell, and make sure to keep it sharp! Don't get lazy. Makes a huge difference.Do you put a flat tip on the tungsten? What size?Nope, 1/8th diameter tungsten, red tipped.How much stick-out do you use?Depends where I'm at in the process. It all varies.Depends on how I feel, fitup, how quick i'm moving that day. etc...More stickout for the root say 1/4 or more past the cup if I am freehanding it.Walking the cup 1/4 does me good.For the hot or fill I like much less.Gas lens, ever?Yes.What gas mix do you normally use?100% Argon is what I was trained on and use.What is your flow set at?18 cfm works for me.What amperage do you use?All varies ~ root around 100. I weld tig hot. Hot +5, and I generally end up around 120 when tigging it all the way out. I run 7018 out at around 80-85. I run 7018 a little colder than many.What size filler rod?Depends on how quick I want to move. Can use either.When I was first learning ~ to tig all the way out the 3/32nd was much easier to control and use. Now I can just roll over it and melt it all in.Do you sand off the protective coating on the filler rod?YES, I do, instructor told me to initially and it's what I learned.Supposed to remove some of the impurities. Don't know that it's needed? But I do.The root weld:Do you use a purge system to protect the root?Not on carbon, stainless I'm not experienced with BUT, you do.What pattern do you use to complete the root? (start position, second quarter, ect.)Start on the bottom 6:00 and work up.Do you grind out your tacks as you go?Yes, on the root. I feather the tacs on the ends and go from there. If I put a small initial tack in I'll walk right over it..How much build-up on the inside of the pipe? (how much is too much?)Flush is fine, a little build up is better ~ just make sure to get an inspection mirror/flashlight to stick inside the pipe and inpsect to make sure the walls are broken down. IF THERE IS A SPOT yous missed? You can generally fix it with a little heat on the hot pass QC might not lie it though.....But it is an easy way to fix an error.What does the outer side of the root look like? (wet in flat?, kinda wet in?)Smooth, generally pretty fla, slight crest I suppose.The hot pass:What amperage do you use? I turn it up +5 generally.How far do you weld before you wait for the pipe to cool?Generally around 30 minutes.Quantity/Speed:How many full joints do you do a day? (and how long is your day?)Do you have a fitter, or do your own fitting?10's, and I don't fit a damn thing, I can average on an hour if i'm cooking.It's good enough to not get run off.My instructor was 10 times faster than me....Last question,What industry are you doing these welds for?All over. Gas / oil primarily.Thanks in advance, I know I'm asking a lot here.Your answers will help me set up and practice as if I were in a real-world situation. That way, when I get out of school, I'm not just another dip-$#!+ that's fresh out of school. At least I'll have half a clue.
Reply:I just read the above post and by the end I started to think I was on the wrong website. Often when a question is asked around here, the poster is flamed for 2 pages. You might want to redo your post jsm, you might get a bad reputation for posting in-depth, useful information
Reply:Originally Posted by JoshDI just read the above post and by the end I started to think I was on the wrong website. Often when a question is asked around here, the poster is flamed for 2 pages. You might want to redo your post jsm, you might get a bad reputation for posting in-depth, useful information
Reply:Originally Posted by ElectricSquidI've been in welding school for over a year now and have asked each of these questions. I have received very good answers from a very knowledgeable instructor. But keep in mind that the answers are coming from one welding instructor, based on that instructors experience, not from the broad spectrum of welders in all the various industries in the trade. Also, things may have changed a little bit since my instructor has worked on boilers, or oil pipelines. Companies may be demanding more work/production per day per worker than just a few years ago. It is these slight differences I'm looking to figure out.I never expected any one person to answer every question. But collectively, a lot of up to date knowledge can be shared with not just myself, but any other that would like to compare what they are doing to others in the trade.LOL The copper coating on the TIG filler rod, not the flux coating on the 7018 electrode.
Reply:Thank you jsm11, for taking the time to share all that information with the rest of us. I know it took some time to write that out. I'm sure others will find it very helpful.Thanks tubr rat 72 for your input.Thanks Josh and Rick for your support in staying on topic.In all fairness, I should take the time and share my own settings. A few of these answers are N/A because I'm not out in the field yet, so I answered them accordingly.The pipe:What size pipe is the norm?How is the joint prepped? (angle, gap, smoothness of the joint face)How many tack welds and how long are they?6" SCH40 with a 37.5* angle (75* included) sanded smooth to a knife edge.Gap is in the range of 3/32" to a hair under 1/8"Four 3/8" to 1/2" tack welds @ 3,6,9, and 12 o'clockTIG set-up:What tungsten size and cup size do you use for the root?What angle do you grind your tungsten tip to?Do you put a flat tip on the tungsten? What size?How much stick-out do you use?Gas lens, ever?What gas mix do you normally use?What is your flow set at?What amperage do you use?What size filler rod?Do you sand off the protective coating on the filler rod? Consistent tungsten preparation is VITAL. I take these following settings very seriously, especially the tungsten tip preparation and tungsten stickout. These settings MUST be the same every time you reset the torch, otherwise there is no way the weld will be consistent.I use a Weldcraft WP-26 torch handle#5 cup for the root, #7 for the hot/filler pass (I like to be able to see what I'm doing)A hair over 3/8" stickout (root & hot pass)1/8" 2% Lanthanated tungsten ground on a 22.5* angle with a 1/16" flat tipNo gas lens (yet)100% Argon shielding gas @ a 20cfm flow rate1/8" filler rod (root & hot)120 to 135 amps (yes, I can move that fast and have complete fusion inside and out with 1/64" root buildup inside the pipe, no concavity, and fully wet in with no undercut. These amperage settings were checked using a calibrated amp meter while in mid weld.)I don't sand off the copper coating, but might start doing that if I find out the copper coating can taint the weld.The root weld:Do you use a purge system to protect the root?What pattern do you use to complete the root? (start position, second quarter, ect.)Do you grind out your tacks as you go?How much build-up on the inside of the pipe? (how much is too much?)What does the outer side of the root look like? (wet in flat?, kinda wet in?)No purgeAll uphill weldingTo start, I choose which top quarter is the widest gap, and weld it first. Because of heat travel, the widest gap on the top of the pipe is most likely to be my problem spot when it's hot, so I weld it first while it's still cool. Then I weld the opposite quarter on the bottom of the pipe. For example, if I weld from 9-12 first, I'll do 6-3 next, then 6-9, and 3-12 last. If I'm running at 120 amps, I need to wait a couple minutes after the first two welds to do the second two. At 135 amps, I've spent so little time heating the pipe, that all 4 welds can be done without the pipe reaching 200* at 3" from the weld. Hot, fast, get in, get out.I grind landings on my tacks, and have learned how to successfully tie into them.As stated above, my root buildup inside the pipe is about 1/64", completely wet in on the inside and outside of the weld.The hot pass:What amperage do you use?How far do you weld before you wait for the pipe to cool?At 135 amps for the root, and completely wet in, I find no need to turn the amperage up for the hot pass. It wets in well at 135. But, that being said, I have played around and did a few hot passes at 151 amps successfully. These amperage settings were checked using a calibrated amp meter while in mid weld. It's fast, but wets in really nice, and if you can move that fast it won't suck the root in. (I can see the disagreement coming a mile a way on this one, so if you don't believe me, come watch me some day and I'll prove it to you)Quantity/Speed:How many full joints do you do a day? (and how long is your day?)Do you have a fitter, or do your own fitting?Because I'm in school, I had to do a little calculating to figure out the daily production number for actual weld time. As it stands now, I can produce four 6" SCH40 pipe welds (TIG root/hot 7018 fill/cap) in one 10 hour day. That was calculated by excluding all the time taken throughout the day not welding and excluding set-up, tear down, and cleanup time.As far as having a fitter, I've been in construction for over 15 years now which is long enough to know that if you want it done right, do it myself. I do my own fitting now, and dread the though of being stuck with a lame fitter in the field. I know some people are great fitters, so I mean fitters in general no disrespect. I just hope that if I have to work with one, that he or she takes their job quality seriously.Last question,What industry are you doing these welds for?N/A - I'm still in school..Last edited by ElectricSquid; 03-09-2011 at 10:58 AM.
Reply:Originally Posted by ElectricSquidTo start, I choose which top quarter is the widest gap, and weld it first. Because of heat travel, the widest gap on the top of the pipe is most likely to be my problem spot when it's hot, so I weld it first while it's still cool.
Reply:Originally Posted by CEPThat's interesting! I always go after the narrowest gap first. When the joint shrinks I don't like too tight of a gap, I can handle larger gaps, just not the tight ones.
Reply:Anyone else?
Reply:Goto correct myselfFor tig root my amps are 100 not 82 or what ever I said before. 90 to 100. Probly closer to 100. Sorry for the missinfo.G |
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