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Up Topic Welding Industry / Technical Discussions / Welding Procedures H2S
- - By carreragas Date 07-28-2005 13:54
We are planning to construct an 8"-0.250" thick and 6"-0.188 thick pipeline that will carry natural gas containing up to 600 ppm of H2S and 0.5% CO2. There will be water present. The operating pressures will vary from 400 to 800 psig. The pipe material will be API 5L X42. My question is, do we need special welding procedures or special filler material to insure that we do not have any stress cracking in the welds? Our current procedures call for X60 rods.

carreragas
Parent - - By jon20013 (*****) Date 07-28-2005 15:39
What is the code of construction?

You may find yourself having to look into NACE MR0175 or an API Standard to make this determination.
Parent - - By carreragas Date 07-28-2005 16:01
We are welding to API 1104, but the welds will need to produce a weld with a hardness less than Rc 22 and we may fall under NACE MRO 175. Our current procedure uses 6010 rods for the root, and 8010 for the other passes. I am looking for a procedure that will produce acceptable welds that will not require stress relieving. This is a cross country pipeline. Is anyone aware of an off the shelf procedure that will work?
Parent - By jon20013 (*****) Date 07-28-2005 17:05
I'm not aware of any off the shelf procedure that would work and I'm not sure you'll be able to avoid stress relieving. Good luck, maybe others will be more useful than I could with suggestions!
Parent - - By G.S.Crisi (****) Date 07-28-2005 18:34
If I were you, my first big concern would not be the welds but the pipeline material itself. H2S and CO2 are corrosive to carbon steel when moisture (i.e., water) is present. 5LX 42 (carbon steel) won't last very long in such an environment.
I'm not familiar with NACE MRO175, but, as Jon suggests, you better take a look at it. For a natural gas pipeline the applicable code is ANSI B31.8, unless the piping is within a refinery (or chemical plant) limits, in which case it falls under B31.3. Read them carefully. Do they say anything about service in a corrosive environment? I don't remember in this moment.
Regarding your welds, I'm surprised that you'll use E8010 for the subsequent passes. Traditionally, in a pipeline a cellulosic electrode (Exx10) is used for the first pass (good penetration), and a low hydrogen (Exx16 or 18) is used for the subsequents (good x-rays testing properties).
If the specification says that the completed weld must have a maximum hardness of 22 HRC and you don't achive it, then there's no other chance but PWHT it.
Giovanni S. Crisi
Sao Paulo - Brazil


Parent - By jon20013 (*****) Date 07-28-2005 19:17
Giovanni;

I too was very surprized by the subsequent passes being with cellulosic electrodes, very unusual in my experience. As you say, normally all passes out from the root (and perhaps hot pass) are with low hydrogen type electrodes tends to be "normal" proactice.
Parent - - By - Date 07-28-2005 21:21
Jon, I couldn't find anythig in my NACE MR0175 that is specific to this question Then, again, I might have overlooked it. I just got back to my office in Dallas from driving all day, so my eyes might not be working like they should. :)
Parent - - By JTMcC (***) Date 07-28-2005 22:22
I don't know where you guys have seen LoHi fill/cap on cross country pipelines, but it's not in the United States. You'd be very hard pressed to find any cross country line welded with 7018. I'm pretty sure I've never heard of nor seen such a thing, my "old timer" pipeline friends have been in the game for well over 30 years and before 70+ the standards were shield arc 85 and the wretched old "hippy" rod. Before there was 5P there was P5, it had a white coating.
The standard is as the poster said, 5P+(6010) bead, 70+ (8010)fill/cap.
Downhill of course. Lincoln has a line of downhill LoHi, I've got a small amount of it but haven't seen it used on a real job.

JTMcC.
Parent - - By G.S.Crisi (****) Date 07-31-2005 22:55
JTMcC,
I've got with me Lincoln catalog nÂș 2112-2, dated May, 1964, that specifically recommends to weld high pressure pipelines with Fleetweld 5P (E6010) for the root pass and Jetweld LH-70 (E7018) or LH-90 (E9018 G) for the subsequents, depending on the grade of the 5LX pipeline.
Giovanni S. Crisi
Parent - By JTMcC (***) Date 07-31-2005 23:09
With all due respect, just because Lincoln printed a recomendation in 1964, doesn't mean it ever was actually put to use in the field. I'm a pipeliner and everyone I know is a pipeliner. There hasn't been a major cross country line welded with LoHi in the United States, ever.
The "oldtimers" I speak of have been involved with every major line laid in this country during the last 35+ years.
Lincoln has printed literature, as we speak, recomending their downhill LoHi rod for cross country lines, and recomending their flux core wires as well. None have been used in a major line. There is sometimes a wide difference between sales literature and what's actually used on the right of way.


JTMcC.
Parent - - By JTMcC (***) Date 08-02-2005 00:18
These "oldtimers" have worked lines from Maine to California, and Alaska to Mexico, plus lay barges in the middle east, south east asia and many other countries. These are the men that have set the procedures for many pipelines all across the world. They have several faults, but memory of consumables used is not one of them. They can still tell you who set the procedure/who was the welder foreman/who was the spread man/who was the steward/who had inspection on pipeline jobs from the Kansas to Saudi Arabia.
Have you ever set foot on an pipeline ROW in the U.S.? Or anywhere else in the world???
The pipeline community is a small, close knit bunch, as they say, there are no secrets on the pipeline. Everyone knows who is on what job and where. The structural welding world in comparison is vast and huge.
Do you have any practical experience to back your claim other than Lincoln sales literature from 4 decades ago?
I'm willing to stand by my comments, and post references. Not much happens in the pipeline world that doesn't go thru the grapevine very quickly, in fact nothing does.

JTMcC.
Parent - - By G.S.Crisi (****) Date 08-05-2005 19:36
JTMcC,
I'll answer your questions one by one.

1st. This is the second time that a phrase which I wrote in this Forum just as a "good humor comment", and was to be considered as that, is misunterstood. I had no intention to offend anybody whatsoever.
Evidently, you Americans have a different mentality, or psychology, than we Brazilians do. A phrase that would make us Brazilians smile make you Americans to become strongly upset.
I've learned the lesson, and from now on I'll limit my postings to strictly answer the questions, with no other intention. As a proof, I've erased from my previous posting the phrase you didn't like.

2nd. I've never lived in the U.S. and therefore I won't argue with you about the electrodes they used in the U.S. to weld pipelines. What I'll say is that here in Brazil, and in other South American countries, which are the ones I've worked in, the standard practice to weld gas and oil pipelines was to apply the root pass with E6010 and the rest with low hydrogen electrodes. I say "was" because nowadays pipelines are welded mostly with automatic machines, which I believe must be the standard practice also in the U.S.
Granted, there are welds that can not be made with automatic machines, and those continue to be done as they were in the past.

I've never lived in the U.S. and won't argue with you, but you can take a look at the "API 1104 Pipeline Welder" question posted by Arnie Capuz on the "Certification and Qualification" section of this Forum, and you will read the comments posted by Arnie Capuz himself, who worked for clients like Bechtel; and Donnie Mann, who worked for clients like the U.S. Army, and they are accostumed to use low hydrogen electrodes to weld pipelines. Also Jon 20013 is accostumed to use low hydrogen electrodes for pipelines, in an answer he posted right before this one.

3rd. Before becoming a university professor, which, I agree with you, doesn't mean very much in terms of practical experience, I've worked for 35 years in engineering projects, some of them quite small (100.000 dollars) and others very huge (3 billion dollars, "bi" not "mi"), either in the office or on the field, and in a wide amount of areas: oil refineries, chemical and petrochemical, metallurgical, power plants, natural gas compressing and oil pumping stations, cement factories, mining, water works, environment protection.
Consulting engineers and/or process licensors were companies as:
Oil refineries: Lummus, M.W. Kellogg.
Chemical: Power Gas, Mitsubishi, Krebs, Covagri.
Petrochemical: Badger, Toyo.
Power plants: Sargent and Lundy, Gibbs and Hill, Merz and Mc Lellan, Ansaldo, Sofrelec.
Gas compressing and oil pumping: Sadelmi.
Mining: Davy Mc Kee.
Metallurgical: this was the largest project (the 3 billion dollars one) and consisted in an aluminum plant for the Aluminum Co. of America (Alcoa).
I'm just listing the American, European and Japanese consulting engineers and process licensors, not the Brazilians, because you don't know them.

4th. You may ask yourself how it comes that in Brazil, a third world country, I had the chance of working in such large projects with such prestigious companies.
The reason is simple: Brazil is a third world country because 5% of the population are billionaire (again, "bi", not "mi") and live in richness and magnificence, while 20% of the population live below the limit of poverty. From an industrial point of view, however, Brazil is more developed than many countries that are considered first world ones.

Regards
Giovanni S. Crisi





Parent - - By JTMcC (***) Date 08-05-2005 21:56
You seem to be seriously offended. That is a grand resume you posted, but nothing in it gives us any indication that you've ever worked on a cross country pipeline which is the topic at hand. If you consider your expertise in other fields as a license to comment authoratively on things you've never done, then so be it. Being a "university professor" doesn't qualify you to comment on consumables used in American pipeline construction either. But the tone of your post tells me that you are used to throwing that term out and gaining instant respect, admiration, praise and perhaps worship from your fellow countymen. That isn't working here. Expertise in the topic at hand would be helpfull though. Admit it, an experienced pipeline welders helper is more qualified to comment on this topic than you are.
I stand by my comment: there has never been a major pipeline built inn the U.S. using uphill LoHi consumables, period. And no, the automatic processes are only used on a limited scale in this country to this point. That will increase as time goes by of course. Tie ins on automatic welded lines are being made with dual shield, not LoHi.

JTMcC.
Parent - - By Kidoman (*) Date 08-23-2005 16:02
Try not to get so worked up. The guy was just replying. I make mistakes all the time and I have been in an inspection family all of my life and I even started inspection myself in 1979. The biggest thing is, like on guy said, never say never. It has happened with lines I have laid in the past. 6010-7018. Not normal, but it happens.

My great-grandad, grandad, dad & uncles have been inspectors since welding with coat hangers, I have seen that done.

Chill, you are not the only inspector on the forum with experience, I can promise you that. Have a great day =)....

Durham (remember any of those guys?)
Parent - By JTMcC (***) Date 08-27-2005 04:15
I'm not an inspecter, I'm a welder.
You say you've laid a pipeline using 7018? When and where?


JTMcC.
Parent - - By thekoz (*) Date 08-05-2005 20:40
I have inspected about 50 stopple tee insallations and sleeve repairs for in service pipelines for a particular pipeline company. The procedure was 6010 root pass followed by 7018 for the balance. the procedure even utilized a tember bead technique for softening the toe of the weld where it met the carrier pipe. These inspections took place in Wisconsin and Minnesota. Never say never! I do know that the use of 7018 is not standard for new line construction in the USA, so don't flame me.
Parent - By thekoz (*) Date 08-05-2005 20:47
BTW I also watched as one pipeline company in Missouri GMAW'ed a hot tap branch tee connection to a 10" main. I never would have thought I'd see a gas shielded process used anywhere in the field on a pipeline.
Parent - By JTMcC (***) Date 08-05-2005 21:46
Right you are, LoHi is most common on sleeve repairs. The only exception I've heard of is dual shield wire.
Of course a sleecve repair has nothing to do with new construction, as you mentioned.


JTMcC.
Parent - - By 357max (***) Date 07-29-2005 13:53
Hippy = HYP. High Yield Pipe. Use 6010 downhill for the root pass, 7048 down hill - low hydrogen for the hot fill and cover passes. You may even encounter 0.120-125 wall thickness 4-6 inch diameter pipe. That requires XX10 root pass downhill and 7048 cap pass for normalizing. 7048 can also be used for root, hot to cap downhill. That would take care of any question about hydrogen in the weld. With skill the 7018 can also be used downhill. If in doubt qualify the procedure and the welders to the procedure.
Parent - - By carreragas Date 07-29-2005 14:13
OK, I am going to show my lack of welding knowledge here. I like the idea of the 6010 downhill for the root. Can we use the 7018 uphill for the other passes? Another way to go would be to ues the 7018 for all. What are the advantages of the 7048 rod vs. the 7018? I know the welders don't like to weld uphill. We are welding 6" .188 and 8" .250 API 5L X42.

Thanks for your response.
Parent - By 357max (***) Date 08-02-2005 16:34
You could use 7018 vertical up for the cap pass. The problem is the pipes thin wall (188-250-3/16-1/4inch) 60degree included angle. Putting the root in without too much reinforcement on the inside of the pipe leaves very little room in the groove for a cap pass. Then with -18 going up without overwelding at a production rate of speed. That is why the 120-188-250 pipe wall thickness is welded downhill with the cellulose -10's, great speed and excellent control on root penetration and weld reinforcement. Bad part is, if hydrogen is a problem, and with H2S it could be. Therefore 7048 low hydrogen is available and it allows downhill travel for root to cap welding. Airco had a CODE-ARC 7048 and when Lincoln bought Airco I believe it disapeared and became the Murex 7048. ESAB has OK Femax 53.35. Washington Alloy Company has USA 7048, Thyssen Specialty Steels has B80. There may somebody else out there who makes it. And as in my previous post, 7018 has been used downhill by qualification of a procedure and qualifying welders to that procedure. The high iron powder 18s are difficult to run downhill, use a low, very low iron powder coating, its different but not difficult.
Parent - By supermechanic (**) Date 08-01-2005 22:15
7048? Not familiar with 7048, what are it's charactoristics?
I've been doing this stuff since 1976, this is the first I've heard of a wire that runs in the "4" position.
Parent - - By Arnie Corpuz (*) Date 07-30-2005 12:16
I am a pipeline/welding inspector and I'm involved in a gas pipeline installation right now. I believed this would give a bit of information for the subject being discussed now.

The said pipeline is a 6"x 14.27 mm (.56") API 5L x60 material and considered as a sour servie line. The design code is in accordance with ASME B31.8 with an operating pressure of 6670 psi. (460 bar). Our existing welding procedure meets the requirement of API 1104 and Shell DEP specification.

The root pass is welded by E6010 downhill progression and all the remaining passes by E8010-G uphill progression. There is no stress relieve requirements on this procedure and the average hardness value (Hv10) are the following; 177 for the PM, 173 for the HAZ and 182 for the WM. I would suggest you to give more emphasis in the interpass temperature to control the heat input that will meet your hardness requirements.
Parent - - By G.S.Crisi (****) Date 07-31-2005 22:35
I insist that Carreragas should pay more attention to the corrosion protection of his pipeline, considering the presence of H2S and CO2 in a moist environment.
Arnie, you said you're using 5LX 60 (another carbon steel) for a SOUR (acid) environment. What do you mean for sour? What corrosive agents are present? What's the concentration? Does the thickness of 0.56 inches (14.27 mm) includes any corrosion allowance?
Let's take into account that carreragas' pipe is only 0.188 inches (4.78 mm) thick. Granted, the pressure is much lower, but I doubt that a thickness of 0.188 inches for a pressure of 800 psi includes any corrosion allowance.
Giovanni S. Crisi
Parent - - By Arnie Corpuz (*) Date 08-02-2005 07:30
Sour Service is defined as fluids containing water as liquids and hydrogen sulfide exceeding the limits set forth in NACE MR 0175 Sec.1.4.1.1. There is a design corrosion allowance of 1 mm for the thickness of 0.56" (14.27 mm). I am not fully aware of the concentration of the corrosive agent, What I understand is that our gas injection pipeline is design to a sour service or sour environment.

I have no idea if there is any corrosion allowance of carreragas pipe. But if ever I am the designer of that pipe I will make sure that a corrosion allowance will be included in the design particularly in such condition.

Finally, I have no objection if Carreragas will pay more attention to the corrosion protection of his pipeline, I believed it will be beneficial to the life span of the component.

Arnie

Parent - - By G.S.Crisi (****) Date 08-05-2005 19:43
OK, you've taken precautions against corrosion. I strongly recommend carreragas to check whether or not corrosive conditions have been considered in his project.
Giovanni S. Crisi
Parent - By Shane Feder (****) Date 08-06-2005 09:55
Greetings to all from downunder,
I have worked on numerous pipelines ( oil, natural gas, methanol and slurry) in Australia and New Zealand as a welder, radiographer and finally as a CWI.We predominately used API 1104 and also the Australian equivalent AS 2885.
Very small pipelines (these would not be classed as cross country pipelines)were sometimes welded with E6010 (downhill)/E7018 (uphill)combinations but there was usually no requirement for speed.
99% of pipelines I have worked on have been welded with E6010 (downhill) / E7010 (downhill) as it is the quickest way to join two pieces of pipe together and that is the most important reason.
We had our welding rigs mounted on Cat D7 dozers and one welder would run bead, one run hot pass, one run fill and one run the cap. The dozers were continually crawling along and if you didn't complete your run in time the handpiece was ripped out of your hand and you had to haul ass to the next butt pronto.
I have never heard of the 7018 being used to run downhill but if someone has managed to qualify a procedure with it then it must be OK to use.(although I won't be trying it)
Regards,
Shane
Up Topic Welding Industry / Technical Discussions / Welding Procedures H2S

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