6" pressure help

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im trying to do my 6" pressure test but dont have alot of time to practice....ive ran a couple joints quickly and am starting to get it but i need some tips....especially for my heat input settings6010 root   7018 hot pass and capim using a 3/32 land and gap with a 3/32 rod for the rootthe root is going in decent but could be a little prettier...i think around 75 ampsactually one of my biggest problems is the hot pass.....i cant seem to find the right setting and am getting quite a bit of undercut.....especially in the horizontal position.....do i want to fill the hot pass up right to the top edges of the bevel ???basically if anyone could maybe guide me thru their process and the tips and tricks of the different welds and positions it would be of great great helpthanks guysjustin
Reply:What wall thickness are you welding? If it's thin wall like .188 then it would be no problem to fill the bevel oN the hot pass you could probably get away with it on .250 wall too but only if your not scared of the heat. Any more than .250 wall and I'd say it needs a filler also. Really hot smoke ring of a hot pass and a filler. If you try to fill too much with the hot pass it'll trap slag. Uphill root? Downhill root? I need to know if I'm gonna give pointers on that. And i hate when people ask about heat settings case there's not a specific setting that'll work every time. For me it's the feel of it. What ever my gut says is what I put it on. But I always weld with my Lincoln and I've put about 1200 hours on it by myself so I'm pretty familar with it. I can look at the gap and guess the right heat every time.I know I may be burnt up, but your ol' lady likes 'em crispy!Member Pipeliners Union 798
Reply:By the way I don't normally fill/cap 7018 I weld everything pipeline style downhill 6010 root and 8010 downhill fill/cap so I may be screwing you up. It's been a long time since I've done 7018 on pipe I'd have to get the feel of it againI know I may be burnt up, but your ol' lady likes 'em crispy!Member Pipeliners Union 798
Reply:like previous responders said, we need to know the pipe schedule or wall thickness to give you advice on the bead sequence.Welding position would help too.  6G or 5G?Your heat for the root sounds about right.  Hot pass are you using 3/32" 7018  or 1/8"?  I find I have less trouble using 3/32" 7018 uphill for the hotpass.There's more room to weave the puddle and avoid undercut.  If you're seeing undercut with 3/32" filler rod, you're probably not pausing long enough.  Keep that drag angle about 10-20°.  If you're testing on schedule 80 pipe, you definitely don't want to fill the joint up wiht the hot pass.  You should be running at least 2 fills on top of the hot pass.  Fill the joint to within 1/16" of flush in the center, then cap.Uphill:Hot pass with 3/32 E7018, I like about 80 ampsFill passeswith 1/8 E7018, I like about 90-100 amps, depending on how hot the pipe is.Cap a little cooler, 85-90 amps.  This assumes you're weaving the beads and taking your time.  I've seen guys fill in one pass with high heat, but I've never liked running that way on sch 80 and higher.   Originally Posted by skoalim trying to do my 6" pressure test but dont have alot of time to practice....ive ran a couple joints quickly and am starting to get it but i need some tips....especially for my heat input settings6010 root   7018 hot pass and capim using a 3/32 land and gap with a 3/32 rod for the rootthe root is going in decent but could be a little prettier...i think around 75 ampsactually one of my biggest problems is the hot pass.....i cant seem to find the right setting and am getting quite a bit of undercut.....especially in the horizontal position.....do i want to fill the hot pass up right to the top edges of the bevel ???basically if anyone could maybe guide me thru their process and the tips and tricks of the different welds and positions it would be of great great helpthanks guysjustin
Reply:I like to use 60-65 amps for my 6010 root bead with 3/32 root gap and 3/32 land. I test on sch 160 1.5" pipe in 6G so there's plenty of meat there. After my root pass is in, I'll grind it down and run a hot pass with 6010 and a "C" weave pattern. Then I go to my 7018 fill and cap passes (still 3/32) at about 80-90 amps. Your amperage really is not set in stone. It depends on your welding machine and your comfort with it's ability.Last edited by snoeproe; 08-31-2009 at 10:01 PM.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:Try reducing your root gap to 1.0mm with 0.5mm land.6010 Root pass amps - Use manufacturer's recommended setting ranges, lower end for WT < 6.0mm and upper end for thicker sectionsGood luck
Reply:its a sch 80, 6" pipe.....overhead both ways....uphill......horizontalright now because im practicing with what i could find and hide at work which is 4 inch pipe....i think about .337 (which is a bit thinner than the test) ....i know its not the same size but i just need to get the basics down now....the size wont be a problemi did a third joint last night and i got a feel for the 3/32 root although i think i need to push the rod in a bit more on the overhead....on the hot pass im using a 1/8 7018 and im not quite sure what its sopposed to look like....i tried filling up almost flush for the most part...i had quite a bit of undercut whether i filled it up alot or tried to keep it in the bevel.....i think im going to try a 3/32 7018 my next time around and keep it a bit lower and neater....maybe the same for the capanyways i really want to get my pressure ticket and im just looking to get some help....i dont really have anyone to ask right now let alone a mentor in the game....been in it blind since the beginning
Reply:Skoal,I'm not 100% sure I understand what you mean by "overhead both ways".  Take a look at the picture shown at the link below.  It explains the short-hand terms 1G, 2G, 5G, and 6G as they pertain to pipewelding.  Which position(s) are you welding in?  I'm assuming you're testing in 5G or more likely 6G, but I want to be clear.http://www.tpub.com/content/construc...s/14250_55.htmTry the 3/32 E7018 for the hot pass.  For the 4" sch 80, I'd fill the joint no more than 1/2 full with the root and hot pass.  Switch to 1/8" E7018 and run 1 or maybe 2 fills for uphill travel.  Then cap the weld.Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector
Reply:cellulose electrodes, eg: XX10, XX11 should be used vertical down for positional applications.With pipework, commonly known as "stove piping"Cheers
Reply:All our pipe has to be uphill welded. No downhill pipe welding is allowed at my place of work. That's the first thing the inspector tells us at test time, no down hill or we fail and he's been around long enough that he can tell.Downhill pipe welding is whats practiced by long line pipeline welders welding on low pressure pipe because of it's speed of getting the job done. It's a no no on pressure pipe.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:Transmission pipeline for the petroleum and natural gas industry is welded downhill, and some of that is fairly high pressure(Over 1000 psi).  It's not the same as high pressure steam lines that you find in power plants, but it's not all what I would refer to as 'low pressure' pipe. Originally Posted by snoeproeAll our pipe has to be uphill welded. No downhill pipe welding is allowed at my place of work. That's the first thing the inspector tells us at test time, no down hill or we fail and he's been around long enough that he can tell.Downhill pipe welding is whats practiced by long line pipeline welders welding on low pressure pipe because of it's speed of getting the job done. It's a no no on pressure pipe.
Reply:ya, your correct. But that is what I refer to as long line pipe welders where the speed of work is critical.Our plant frowns on the downhill pipe welding for the reason you stated, high pressure power plant. Uphill pipe welding only.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:Originally Posted by snoeproeDownhill pipe welding is whats practiced by long line pipeline welders welding on low pressure pipe because of it's speed of getting the job done. It's a no no on pressure pipe.
Reply:This opens up more questions for the uphill/downhill pipe welding debate.What is that 42" transmission line carrying at 2000psi?Why is it that a 2000psi pipe can be welded downhill at one site and a 1400 psi pipe at another site can't? Is it simply a regional pressure vessel code each is forced to follow?JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:Natural Gas is the most likely answer.  I don't know what kinds of pressures are common for liquid petroleum products.As to why welding procedures differ, I don't know for certain.  I would guess that:The risks involved differ and so the quality control procedures differ.   Welding procedures are all about ensuring certain levels of quality in the finished welds....Operating conditions for the pipes differ.  High temperature steam vs ambient temperature natural gas; as one example.The base metals and filler metals for a steam line would require different mechanical properties, like high temperature strength and corrosion resistance.  Perhaps no one has been able to develop filler metals suitable to the conditions present in steam lineapplication that can also be reliably welded downhill? Originally Posted by snoeproeThis opens up more questions for the uphill/downhill pipe welding debate.What is that 42" transmission line carrying at 2000psi?Why is it that a 2000psi pipe can be welded downhill at one site and a 1400 psi pipe at another site can't? Is it simply a regional pressure vessel code each is forced to follow?
Reply:Originally Posted by snoeproeThis opens up more questions for the uphill/downhill pipe welding debate.What is that 42" transmission line carrying at 2000psi?Why is it that a 2000psi pipe can be welded downhill at one site and a 1400 psi pipe at another site can't? Is it simply a regional pressure vessel code each is forced to follow?
Reply:Originally Posted by snoeproeAll our pipe has to be uphill welded. No downhill pipe welding is allowed at my place of work. That's the first thing the inspector tells us at test time, no down hill or we fail and he's been around long enough that he can tell.Downhill pipe welding is whats practiced by long line pipeline welders welding on low pressure pipe because of it's speed of getting the job done. It's a no no on pressure pipe.
Reply:Uphill / downhill makes little difference to weld quality, provided the corect electrodes are used Cellulose electrodes are primarily focused at downhill pipe welding, the arc is too fierce to allow vertical up welding with any success.If forced to weld vertical up in a positional situation using SMAW on C-Mn steel, electrodes like E6013, E7016, E7018 are best choice.Onshore gas transmission lines are welded using the stovepipe method simply for production due to the high deposition rates achieved.The mechanical properties, ( down to -20°C ), and weld quality achieved with cellulose based electrodes these days is excellent. Brands like Thyssen, Foxcel supply cellulose elctrodes of very low hyrdogen status in hermetically sealed containers. Cellulose electrodes are focused on API 5L grades of pipe from X42 to X80. Low alloy steels including CrMo types used in power generation, ( high creep resistance), eg: P3, P4 are not in the realm of cellolusic rods. Low hydrogen electrodes are used, eg: E9018-B2, B3 etc. These are normally used vertical up in positional situations, however LH electrodes focused on vertical down welding are creeping into the market. I have personally used these with good results achieved. Check out Weldwell PH 27P as an example.I'm not confident satisfactory weld quality and repeatibility can be achieved vertical up with cellulosic electrodes.Cheers
Reply:Originally Posted by JTMcCThere is no debate, the industries (pipeline construction, power piping and boiler/pressure vessel construction) all have a long and widespread knowlwdge base and a fairly long history of succesfull and safe service. The materials and consumables used in those different industries vary a lot but all have been extensivly engineered, tested and proven in use.Boiler & power piping materials deal with a whole different set of conditions than a transmission line, big differences being high temperature and the chemicals involved. Those conditions call for pipe materials that are welded most economically with the consumables that have been refined over decades for that service.....and those consumables are used most commonly in uphill progression.The boiler and power piping workforce is also well trained in the use of those consumables in uphill mode and have been for decades.That's my take, and it's just a very brief take on a complex topic.JTMcC
Reply:I work in the pipeline industry and a 42" line like the one in question is near my house. It is a cross country natural gas line. One of the compressor stations near there has two jet turbine engines pushing the gas. It is flowing a billion cubic feet per day at around 1900 psi hardly what I'd call low pressure. But the different welding codes from pipeline vs industrial plant piping are very different. We weld downhill 6010 root with 8010 fill and cap with x-Ray shooting 1104 code for speed. While plant piping is usually 6010 uphill root or GTAW root and hotpass with 7018 fill and cap shooting B313 code. B313 has to be much cleaner and has stricter tolerances for IPD and slag inclusions or defects. Oh and the wall thickness on the 42" inch 'low pressure' (ha ha ha) line welded to our specs is .880" pretty heavy stuff and the above ground fabrications and road crossings on the same line are 1.000" walls thickness or greaterI know I may be burnt up, but your ol' lady likes 'em crispy!Member Pipeliners Union 798
Reply:Originally Posted by snoeproeThis opens up more questions for the uphill/downhill pipe welding debate.What is that 42" transmission line carrying at 2000psi?Why is it that a 2000psi pipe can be welded downhill at one site and a 1400 psi pipe at another site can't? Is it simply a regional pressure vessel code each is forced to follow?
Reply:Originally Posted by matYou will find most of thoes welders are using, celulose electrodes, thats why then can downhill it. It's also  becoming common for companies to use welders to put the root in and use a machine to put the hot and cap in with dual sheild.
Reply:Originally Posted by wirehuntUp until so many years ago either way would have been fine.  Now the engineers have gotten flower so we want this other **** done. It's slower and more labour intensive so I don't mind, that all equals more money for me  SWEET.
Reply:Originally Posted by JTMcCNot in the United States it's not.JTMcC.