Ring around pipe weld ?

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Hey there guys...I have a quick question. Why is it some pipe welders put a ring around either side of their pipe welds with either a cut off wheel or file ? Make the weld appear straighter?  Clean up under cut ?  or ?And do inspectors have any issue with it ?ThanksJourneyman / Red Seal Welder (What a useless test)Miller CST 280Miller XMT 350Miller 12vs XtremeEvolution Evo 28 mag drillEvolution 380 Dry Cut saw
Reply:It evens up the sides up and makes it look better. It will bust you out with an inspector though. You can also smooth out small amounts of undercut and as long as you don't go deeper that what minimum thickness of the pipe you are fine. When they inspect a weld they use a knife blade and if it catches on the undercut it is a fail. If it is smooth and not too deep it will pass. Any jagged edges will bust you out.
Reply:They also use these methods to clean tiny bits of slag off the welds
Reply:Originally Posted by fronty_78They also use these methods to clean tiny bits of slag off the welds
Reply:When you put in the root pass (AKA stringer bead), the bead has a convex shape and can trap bits of slag between the bead and the beveled ends of the pipe. There is no room for error in high-pressure pipe lines and any bit of slag remaining will cause the weld to fail X-ray.Thus it is common practice to grind, file, or wire-brush the slag lines (commonly called wagon tracks) to make sure no slag remains.Note this is only the root; as chadcooper55 said, grinding your cap is a no-no. JohnLast edited by Silicon-based; 03-31-2012 at 10:01 PM.Reason: spelign!A few weldersA lot of hammersA whole lot of C-clamps
Reply:this will get into those toes and clean em out without making a line like a file normally does.. Attached Images
Reply:I do high pressure pipe work and never failed a visual because I've used a grinder or file on my cap run.Straightening up the toes of the weld and blending stop/starts will make the weld look a lot better when painted too. It's just the reinforcement that you are cleaning up I can't see any reason the weld should fail because you used a grinder on the cap. Unless its unpainted stainless, then obviously minimizing the grinding on the welds is a good thing
Reply:the bead has a convex shape and can trap bits of slag between the bead and the beveled ends of the pipe
Reply:I asked this same question a few years ago on the AWS site, the general consensus was most inspectors will not allow it. I think it makes the weld look better. I need all the help I can get, so I don't mind spending a minute or two with a half round bastard file.  Attached ImagesDon’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:What's the reasoning for not allowing it? You can't tell me that if you did 2 welds, used a file on one and not on the other, that the one you filed will be someway weaker or not up to standard. Here's a few bad photos. I have a better phone camera now so will start taking some decent pics Attached Images
Reply:Camaus, if you can put your knife in the file mark and slide it sideways away from the weld and it catches it is a fail. The code that i work to allows 0 undercut on the cap or root. If you lay your file flat and smooth out a pinch of undercut you will be fine because pipe is made slightly thicker than what is allowed to meet minimum thickness. The sharp edges are what gets you. When you file you are actually adding a weak point.
Reply:Originally Posted by CamAusI do high pressure pipe work and never failed a visual because I've used a grinder or file on my cap run.Straightening up the toes of the weld and blending stop/starts will make the weld look a lot better when painted too. It's just the reinforcement that you are cleaning up I can't see any reason the weld should fail because you used a grinder on the cap. Unless its unpainted stainless, then obviously minimizing the grinding on the welds is a good thing
Reply:Originally Posted by chadcooper55You are correct, you can grind ON THE CAP, not beside the cap on the pipe.
Reply:Originally Posted by Showdog75Most code work has a spec for minimum wall. I do nothing but code work and we can file when needed. One bit of advice is to take a stainless wire brush on a die grinder to the weld after file work. If your good no one will ever know you used a file.
Reply:Most codes say no grinding or filing on the cap.  The ring you're speaking of is when welders tilt the file at an angle and run it around to make undercut not look as bad.
Reply:The pics the guys have posted above are what im talking about.  I have seen in the past an inspector letting it go, guess it depends on the application.I work in a boilershop and its done on all the high pressure welds, but the welds are not inspected by a welding inspector, only a boiler inspector who knows jack about welding, he or she just verifies the hydrostatic test goes ok and checks fit up before a weld is made.Journeyman / Red Seal Welder (What a useless test)Miller CST 280Miller XMT 350Miller 12vs XtremeEvolution Evo 28 mag drillEvolution 380 Dry Cut saw
Reply:It is a common practice in all the shops and welders I have worked with.  I guess it is regional.  It is done to dress the slight errant toe or stubborn slag chip.  all the inspectors use a gauge that have a pointed pick that will tell how deep any inperfection is whether it is undercut or irregularity in a cap.  They have passed some I thought were close and busted some that seemed perfect.  "the gauge never lies" is all you hear.  It is too boring for me so I stay in fab/structural/fitting arenas.  The low pressure and structural pipe I have welded, it doesn't matter as much.
Reply:Can somebody post a pic of how its done?Ranger 305gMillermatic 140 AutosetDewalt Chopsaw2 grindersMy Fists
Reply:Originally Posted by bp626indamixCan somebody post a pic of how its done?
Reply:I know plenty of welders that do it, Hell I used to! That was until we started getting our welfare inspected and shot. I broke that habit quickly when i found out it would fail me. If you learn how to weld properly you don't need to file to make it uniform and cover up undercut.
Reply:I do it every weld, never had a problem with inspection or failing a xray (knock on wood) you aren't digging deep just barely touching the edges. I use a half round file, but allot of my co workers will use a old german hacksaw blade that works pretty well. You know if you have too much undercut because the file wont help you, then you gotta grind out the cap and re weld.
Reply:Welp, here in Port Arthur Texas.... You "ring" a weld at the Valero Oil Rfinery it is a COMPLETE cut out.When you ring a weld you are actually taking away from the base metal. Which in turn can make it weak at the weld.My hood and I... Till death do us part
Reply:Originally Posted by alloycowboyWelp, here in Port Arthur Texas.... You "ring" a weld at the Valero Oil Rfinery it is a COMPLETE cut out.When you ring a weld you are actually taking away from the base metal. Which in turn can make it weak at the weld.
Reply:The welding pattern is very systematic. new welders should learn form such images. Nice post.Last edited by isonyyelon; 04-07-2012 at 01:52 AM.bronx homes for sale
Reply:Originally Posted by alloycowboyWelp, here in Port Arthur Texas.... You "ring" a weld at the Valero Oil Rfinery it is a COMPLETE cut out.When you ring a weld you are actually taking away from the base metal. Which in turn can make it weak at the weld.Originally Posted by CamAusIf someone told me to cut out a perfectly good weld like the one above, I would tell them where to go!What a waste of time and money
Reply:Originally Posted by SR20steveI do it every weld, never had a problem with inspection or failing a xray (knock on wood) you aren't digging deep just barely touching the edges. I use a half round file, but allot of my co workers will use a old german hacksaw blade that works pretty well. You know if you have too much undercut because the file wont help you, then you gotta grind out the cap and re weld.
Reply:at my work we aren't allowed to stensile the weld -only beside the weld.  to me it doesn't make sense because if you stensile directly on the pipe, isn't that like creating undercut ?  would make more sense to do what the guy in this picture does and stensile the weld because you have metal piled higher than the pipe and a root underneath that extense below the pipe.  guess i should ask QC
Reply:Originally Posted by alloycowboyWelp, here in Port Arthur Texas.... You "ring" a weld at the Valero Oil Rfinery it is a COMPLETE cut out.When you ring a weld you are actually taking away from the base metal. Which in turn can make it weak at the weld.
Reply:Taking away ANY of the base metal would put it below its original wall thickness.My hood and I... Till death do us part
Reply:Originally Posted by alloycowboyTaking away ANY of the base metal would put it below its original wall thickness.
Reply:Ok... your random grind mark or punch mark are RANDOM. A ringed weld is a continuous 360 degree of taking out base metal. There is a major differance between the two. If there is a differance in wall thickness from the mill it would be in the 1000ths of a inch. Most ringed welds go way beyond that. The best way to ring a weld and it be ok is to use a air saw blade. Lay it flat. It really scratches. I personally dont ring weldsMy hood and I... Till death do us part
Reply:Originally Posted by alloycowboyOk... your random grind mark or punch mark are RANDOM. A ringed weld is a continuous 360 degree of taking out base metal. There is a major difference between the two.
Reply:Originally Posted by sn0border88No there isn't.  Min wall meets the requirements of the design, regardless of how much of the material is at or close to that specification.  Checking out ASME B31.3 (2004ed.) K304.1 states, "The required wall thickness of straight sections of pipe shall be determined in accordance with Eq. (33).tm = t + c (33) The minimum wall thickness T for the pipe selected, considering manufacturer’s minus tolerance, shall be not less than tm. (b) The following nomenclature is used in the equation for pressure design of straight pipe. tm = minimum required wall thickness, including mechanical, corrosion, and erosion allowance."I post more from the section but you get the point. And no where does it specify how much area can be near min. wall.  As long as its over, it passes.However I did find this in ASME Sect.8 Div.1 "UHT-84 WELD FINISHThe requirements of UW-35(a) and UW-51(b) shall be met except that for SA-517 material the maximum weld reinforcement shall not exceed 10% of the platethickness or 1⁄8 in. (3.0 mm), whichever is less. The edge of the weld deposits shall merge smoothly into the base metal without undercuts or abrupt transitions; this requirement shall apply to fillet and groove welds as well as to butt welds."I'm not very familiar with ASME code, but this language is a little vague to me.  So does ASME require 0 undercut on all pressure vessels?  So it is up to the inspector to determine what an "abrupt" transition is?  I'm hoping Supe or one of the ASME guys will chime in here and clear things up.I know in D1.1 "ringing" the weld is perfectly acceptable, as long as it doesn't exceed the undercut criteria.
Reply:You are missing the point, the min. wall thickness will be slightly thinner than the actual measurement of the pipe to account to things like this.  If the "ring" goes farther than min. wall then yes, it fails.  If it doesn't, then it passes.  Or at least it should in my opinion,If valero wants to cut it out instead of running a repair procedure then that's their baby.Just because a large company does things one way, doesn't mean that it is the best way.  Look at the automotive industry.Have we all gone mad?
Reply:You would be talking fractions of a mm taken off if anything. I don't believe in filing out undercut, but merely to enhance the aesthetics of the weld by squaring up the toes.
Reply:Originally Posted by chadcooper55It isn't a perfectly good weld if you file too deep. It is code so i don't do it. It is not that hard to not file a weld. Any sharp digger in the pipe is basically the start of a crack. That is why undercut is so bad. If there was going to be a failure it would be there. I would get called out on putting my stamp on the weld like the weld pic posted. For us they want them one inch or less from the weld but not touching the weld which I understand because people could use the stamp to hide some bs in the weld.
Reply:It isn't minimum thickness that you are concearned about with filing as much as the sharp edge that you leave. Also we are all arguing about what the code states and what it will allow. We all work in different industries with different inspectors and different specs. I do industrial refrigeration which the pressures aren't all that high but i have huge temperature swings which is very hard on things. I agree that a filed weld is never going to fail but i also know i have to cut it out or repair it if i do it.