Open Root Pass using 7018

Date 02-20-2014 16:39

First point; the welder should be following a written welding procedure specification. Whether welding to API 1104, AWS D1.1, or ASME Section IX, the WPS must be qualified by the contractor employing the welder. The WPS should list the appropriate parameter ranges for the electrode and joint detail used by the welder.

Second point: based on my experience with the open root test using E7018, the root face and root opening should be about the same as the electrode diameter. In my case the root was deposited with 3/32 inch diameter E7018. The motion used is a slight forward to the leading edge and backward toward the back of the weld pool. Never move the arc completely out of the molten weld pool as would be the case using E6010. Keep a short arc length and no side to side motion (oscillation/weave). The hot pass was deposited with 1/8 inch diameter E7018 using a slight weave.

All weld beads were made using uphill progression.

The old timer that taught me to weld pipe was an interesting character. Hans was a tanker in Hitler's army and was taken as a prisoner of war. He was interned in the US. At the end of the war he was offered the choice of staying in the US or going back to Germany. He said his home was bombed and most of his close relatives were dead. There were few reasons to return to Germany,so he elected to stay in the states. He worked for the same manufacturer for many years as a pipe welder. The company had two classes of welders, pipe welders and structural welders. Management made the decision to reclassify both groups as welders with no distinction in pay. Hans refused to weld from that day forward. The company broke him back to a welder's helper, still he refused to weld. Hans took a liking to me when I went to work for the company and taught me to weld pipe, but he never picked up the "stinger" while teaching me. He taught me to use the sound of the arc to gage whether I was penetrating the joint. As he said, "You should be able to close your eyes and tell what the arc is doing."

I can't say that I ever reached the point where I could close my eyes and weld, but his point was well taken. The sound of the arc tells you whether the joint is completely penetrated or not.

Good luck - Al

By jarsanb (***)

Date 02-20-2014 17:09 Edited 02-20-2014 17:31

Is it popular? That depends on where you work I guess. E7018 for root passes has been a requirement where I work in the fossil fuel arena since the 60's. More recently, a requirement on In-Service pipeline maintenance. When I first starting getting into lo-hy roots about 18 years ago I bought a book called Pipe Welding Procedures by Hoobasar Rampaul offered through H.I.W.T. library services. To be honest I didn't find it very useful. If I was more proficient maybe. But I just couldn't get root pass to do what I wanted using the listed technique of an inverted V. If I recall, preheat the side bevel - move back to center and so forth. On heavier wall pipe (> .375) I guess I can see it.

Moving forward. When qualifying welders for this requirement where building trades are involved 'most' of our welders have used a fairly heavy root face and root opening, approx. 1/8". Keeping a very tight arc length with 3/32 E7018 in the center of the root. Very little side movement. When the keyhole starts to get it little out of control, stop, compose yourself, let it cool a little and go at it again (after cleaning stop area).

When qualifying pipeline welders using thinner wall pipe (< .375) they get really nervous if the root opening and root face start to get bigger than 3/32". I just qualified 15 guys a couple weeks ago. E7016-H4 DCEN 3/32's. Again, tight arc length. Consistant speed right up the center. On the branch, a little whip to the run. Amps and volts recorded on WQR's volts/ 18 to 23 - amps 80 ish for the root, 80-100 fill/cap. Keep in mind this was with DCEN E7016. I don't remember the exact parameters on the 7018 off hand but I think the root amps were in the 70's. I personnaly wouldn't touch the root with an 1/8" electrode. I'm sure someone can do it, I've just never seen him. He's probably somewhere in Texas.

Hopefully others with experience will chime in. EDIT -I see Al had responded just before me. He certainly qualifies as someone with experience. I'd run with that.

By dbigkahunna (****)

Date 02-20-2014 18:12

For the root you want to use Kobe 7016. It is designed for open root UH root beads.
The rod diameter you use should be based on the thickness of the material you will be welding. If you are welding Sch 80 8 inch you will not be using a 3/32!
The critical elements of the weld are:
Land Width
Root Opening
Rod Angle
Travel speed
Land Width: It needs to be slightly thicker than the electrode.
Root Opening: It needs to be slightly larger than the electrode
Rod Angle: The rod needs to be kept 90 degrees from the bevel and square with the bevel.
Travel Speed: This is a blind weld. You cannot see the weld puddle as it is deposited. The machine needs to be adjusted to allow a uniform speed the entire length of the weld. My experience with OR 7018 has been with welders using Lincoln SA 200 type machines. Sometimes changing the voltage slightly will made a world of difference. I tell welders there is a sweet spot on that machine that when they find it the weld is almost automatic.
If you have a keyhole, Stop. This is not a XX10 rod. Instead of the sound of sizzling bacon you should only hear somewhat of a hiss.
If the root gap scares the bejebbers out of you, then you have the gap just about right. Unlike the XX10 rods, if you do not have enough gap you will not be able to push it in with the rod. Also if it gets tight on you, the grinder will not be any help as you are thinning the land and that is what the puddle needs to hang on to.
Think caulking gun. You want to run the rod like a caulking gun. Keep the rod pointed straight in and let the machine do the work. You do not want to let your hand drop below or rise above the weld. If you are doing the up 5 down 5 and jerking the rod from side to side, you are working way too hard and the bead will look like hammered do do.
I have seen guys fight and fight this until they get it through their heads, do the prep right and have the machine set correctly and it just flows. And use the 7016 Kobe's.
If you do a search on my user name and Open Root 7018 you will find several post I have made covering this.
If you take the time to learn how to do this you can put on your business card, Weldor.

By 803056

Date 02-20-2014 20:52

Put weldor on your business card and they will think you are older than dirt or a complete hack, shoemaker, or ham and egger. That terminology went out with the dinosaurs and James Lincoln.

James Lincoln used the term weldor to signify the individual doing the welding. He used the term welder to signify the welding machine. AWS standardized the term welder and welding machine back in the 50's if not before.

Best regards - Al

By Northweldor (***)

Date 02-21-2014 19:31

Al:
I am very hurt at being referred to as " ...older than dirt..." etc., even though it is the truth. I would never have suspected that you were a grammatical bigot, given your expertise as a weldor and your experience with welders, but the language will not be frozen by AWS, or others of your ilk, you young whippersnapper!

Here is proof, from one much younger (than me) that "Weldor" lives on, long after Lincoln's death :evil:

http://www.pacificnet.net/~sonia/welding.html

By 803056

Date 02-21-2014 19:53 Edited 02-21-2014 20:00

It was written in 1982! Some of the youngsters that visit this site weren't even born when it was written!! :eek:

However, I grant some latitude to my relatives to the North. I understand that takes a bit of time for the sled teams to get the latest literature up into the North Country.

Even the more recent publication from Lincoln Foundation have finally adopted standard AWS terminology.

If it pleases the court, I rest.

Al :cool:

By welderbrent (*****)

Date 02-21-2014 22:22

Granted, I too got out of school more than one or two years ago... well, maybe even more than ten years ago, but it amazing how we slaughter the language and then change grammatical and spelling rules to make them fit what we are currently employing in our 'American' (certainly NOT English) language.

Not being critical Al. Just following the train of thought and reflecting on some things that were pounded into this young student's brain over 4 decades ago. It is indeed an interesting study of word etymology to see why and when the endings of 'or' and 'er' are/were used.

Anyway, use whichever one you want as far as I am concerned. But, when writing reports for D1.1 AWS standards we really should defer regardless of our personal beliefs.

Have a Great Day, Brent

By ssbn727 (*****)

Date 02-23-2014 05:35

Now don't forget "Whether or Rather" also buddy. :eek:

By kcd616

Date 02-23-2014 06:47

henry be nice
for crying out loud your too smart
now I can never be a cwi
admitted someone is smarter than me again roflmao
sincerely,
Kent

By welderbrent (*****)

Date 02-23-2014 13:44

Henry is just giving me a hard time, though you probably know it. That is one of my problem areas. And I do appreciate his help.

Keep up the fight Henry. You are appreciated around here.

Have a Great Day, Brent

By ssbn727 (*****)

Date 02-25-2014 08:32 Edited 02-25-2014 20:48

It's hard to avoid that temptation Kent! I mean it's all in good fun between Brent and myself and believe it or not, I learned something from Brent the very first time he used that regional alternative to whether so whenever chance I get, I can't help myself to poke fun at it with Brent and he knows that so,no harm - no foul, and I promise to play nice. :grin:

Now on the doubt you have in becoming a CWI based merely on my supposed intelligence (No smarter than you buddy!) forgive me in writing this but, that's a bunch of Malarkey! :eek:

And yes, I know you're only kidding also! :yell:

I hope everything is as good as it can be for you K... I just got back from the hospital again because my oxygen saturation level was getting dangerously low so after the typical round of tests, they came to the conclusion that my left lung is getting weaker again, and now they're going to schedule some time for me in the hyperbaric chamber again to "pump" me up again with plenty of O2 until the next time my numbers drop again... This means that I'll have to go back up to 6 lpm's instead of the 4lpm's I was on before this afternoon's switch back up to 6... So it's one step forward and two steps back again! :yell:

And yet I like the chamber because I can meditate in there like no other place which does get me relaxed and in good spirits so I'm looking forward to that... :smile:

I even got my own seat marked so it'll be back and forth again for at least a month 3 times or more a week yet I won't know for sure until after my first session because they have to use that one as the baseline to see how much I need in order to maintain the desired blood oxygen percentage that they're looking for and then they can estimate how many and how long this round will take to get back to where I was from my last round of getting "pumped" up in the chamber... So I guess one could say that I'm seriously deflated of O2 in order to keep moving and breathing at a relatively normal pace but, I'm really confident that I'll be "re-inflated" in no time because I have been through this already twice and it worked like a charm!!! I just need to slow down a bit in my physical activity level for the time being... Well, I think I'll stay on for a minute or two and then go back to bed and hopefully get more sleep. :eek:

Respectfully,
Henry

By welderbrent (*****)

Date 02-25-2014 09:37

Thanks for the update on one area of your health Henry. I like knowing what is going on with you.

Oh, I'm beginning to think that sleep is entirely over-rated. But I still don't know how some people get so used to working nights. I can not sleep during the day. Maybe I should try an O2 tent :lol:

Have a Great Day, Brent

By kcd616

Date 03-03-2014 02:25

Henry,
just some good fun between friends :wink:

thank you my friend
sincerely,
Kent

By 46.00

Date 03-03-2014 04:25

Henry, my prayers are with you. I have had a period of ill heath , first time ever and pretty serious , and I can sort of appreciate your problems! No where near as bad as yours I doubt, but bad enough for me! But you are and always have been a fighter and I'm sure you will keep on fighting and prove the medical people wrong!

By jherrera (*)

Date 02-21-2014 00:54

You must be careful with hydrogen and poor fussion defects using e7018 for a root pass. Always use a 7018-Hx and a good Welding technique.

By Tommyjoking (****)

Date 02-21-2014 22:09

Have not seen anyone test lohy open rt in a long time. You must have a decent opening to make it fly, do not run it tight like you may on a 5p bead. Lands will be thicker in comparison to help hold the puddle. It is running best when you can keep the rod right in the gap...however I have stepped off each side before (to soak a little heat) keeping the puddle live and put in a good root. I am probably weird to others in I will run a thinner land bout to a thick 1/16 and tighten my gap a little smaller then my electrode then weld about 15 amps colder then normal for that size...the land thickness vs gap will increase with electrode size but I like running that rt with as small a rod as I am allowed. It is easy for your keyhole to get away from you on this test, so prep/fitup is real important. Heck I wish I could find more jobs testing that way.

By dbigkahunna (****)

Date 02-24-2014 02:10

The Kobe 7016 is designed for the root pass for open root welds.
While there are other rods that can be used and I have seen welders use the POS Lincoln rods and pass.
But when you are learning how to make this weld the Kobe makes it a lot easier. And most welders who have to do the ORLH on a regular basis will keep a fresh can ready to go.
Where there is a lot of H2S pipeline this is more common.
Also you need to match your electrode size to the thickness of the pipe. IF you have sch 80 running a 3/32 is a lot harder than using the 1/8 for the root and even a 5/32 if you can handle it.
I have not seen a welder who will take their time and learn all the aspects of the weld who cannot pass this test. But it takes a commitment of time to do it. Remember it is root opening size, land size, rod angle and heat, Wide, thick, 90 degrees and slow.

By Tommyjoking (****)

Date 02-24-2014 03:55 Edited 02-24-2014 04:06

kahunna I understand wanting to test kobe rod on this.......but what about old hang your **** in the wind 7018 open rt test. well that is different ballgame is it not. It really makes no diff....nobody uses this as a spec anymore......those kind of jobs will go to tig rt or 6010 with a quality lohy fill. It is just a diff world.....why push your luck with lohy open rt....very few will meet your requirement and on most engineering disciplines it can be easily avoided. GOD I feel like an old fckr.

I posted a lot more but hell what is the point..............

By dbigkahunna (****)

Date 02-26-2014 02:17

While it is not commonly used it has its place. Repairs. Fix a leaking compressor discharge bottle pipe in a compressor shed with the wind blowing 20 MPH through it with TIG.
A lot of tie ins on sour service where the ferrite content cannot be determined is made with the ORLH. No using tig to tie into sulfur saturated carbon steel. Several gas companies out here in the Permian Basin have this as part of the standard testing procedure. 2 inch and 8 inch sch 80. And you do not get your full papers until you pass the test.
You are right on new construction you would not use ORLH. A lot easier getting welders using TIG and capable of passing the ORLH.
And having walked a bunch of welders though the test, why risk busting the test using 7018 when they let you use the 7016?

By Tommyjoking (****)

Date 02-24-2014 04:09

No bro it is not a new thing......but if you get asked they want to see if you can walk that metal and be clean lohy. It is not that hard to do....but it flies against how you make money in smaw these days.

By Jim Hughes (***)

Date 02-25-2014 13:51

Welder2,
I don't know what part of the country you are from but using E7018 was first intruduced in my world through that great company that invented the farm code, ALCOA out of Pittsburgh PA. When I went to work for them we had to take an 8" Sch 160 test 6G using E7018 all the way. They did have a WPS qualifed to ASME Sec IX. They told us "weldors" that it was because their 50% caustic systems would not attack the root as bad using E7018 VS E7010. So we did it. It was a pain in the behind, but after a little practice, I put a pretty nice root in. In fact I still have a piece of that test on my shelf that I picked up after I cut the straps.

Thanks
Jim

By 357max

Date 02-25-2014 17:00

A good practice machine to get the hang of open root low hy is the syncrowave 250. Set the machine using squarewave ac with the dig control set at maximum. the "pulsing" ac allows a short tight arc with very little electrode manipulation. Then transition over to dc + and lower the dig control to less than 50% on the syncrowave. Syncrowave is suggested because with some squarewave ac machines the dig control does not work or is not functional with ac smaw. To test to see if the dig control is functional - set the machine for ac and the amperage needed; dig control at "0" and strike an arc and shorten it real tight. Observe the amperage reading. Then just increase the dig control to maximum (100%) and repeat weld with tight/short arc length. If it is functional there should be a substantial increase in amperage.

By Lawrence (*****)

Date 02-25-2014 18:16

I was going to mention AC for the open Lo/Hy roots... But was worried that it would conflict with WPS's.

The Skills U.S.A. World Championships use Low Hydrogen electrodes for open roots on pressure vessels and the students all use AC.

I didn't even think about using it for practice... Great idea.

Also... The Synchrowave 250 is the best open root pipe machine I've ever used... Good call there too :)

By 357max

Date 02-25-2014 18:38

Alas the infernal WPS; a good test is worth a thousand opinions. A qualified wps with an AC root with hot fill and cover with DC+ would be like having a qualified wps with DC - GTAW root, DC+ SMAW with hot fill and cover. The squarewave ac usually is produced from a single phase power source versus the three phase DC only machines. This could cause some welders to have heartburn; that is, a sound weld could be made with a single phase ac weld output.
With the newer ac inverters the question would be; would the ac weld output have the fully functional adjustable dig control? ...Something to try.
For seasoned welding students who know (because they were taught this) an E6010 cannot be welded with AC. Squarewave AC especially with the dig control increased produces an E6011 like arc. Now that would be an interesting wps to qualify. It definitely would be a great application for root pass with a magnetized material.