ERW vs Seamless pipes 6

[engresague]

Hi,

I am involved in a work of laying of pipe line, and the contractor proposes to use ERW pipe instead of the seamless pipe established by the original engineering. I have been consulting the normative references and do not get the limitation to the use of ERW pipe in services such as fuel oil (120PSI) in a submarine lying.
Can anyone recommend me something about it or tell me that I find reference document?.
Thanks in advance for your help...

 

[bimr]

You might consider a search on the site for the particular issue that you have. There have been a number of ERW vs seamless discussions:

http://www.eng-tips.com/viewthread.cfm?qid=5297

http://www.eng-tips.com/viewthread.cfm?qid=311338

http://www.eng-tips.com/viewthread.cfm?qid=3872

http://www.eng-tips.com/viewthread.cfm?qid=98839

 

[noxnoxmox]

ERW pipe surface quality is much better than the seamless steel pipe .

In terms of corrosion ERW can last longer than seamless pipe roughly 3-4 years longer. Though the price is expensive for ERW. It really depends on the manufacturer if they provide it for long pipe distance.

But generally Seamless pipe is more recommended.

Hopefully it helps.

 

[LittleInch]

As far as I know the design codes for pipelines make no difference to the wall thickness/stress calculations between seamless and ERW. Thus it comes down to past experience and personal preference, but for a pipeline at that pressure (you don't say how big it is) it would seem to make no real difference.

For smaller pipes and plant pipework, seamless is preferred due to ease of cutting and screwing, but for pipelines it doesn't really make any difference, just rotate the seam weld 60 degrees off from the previous one and no one will complain.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[moltenmetal]

For small sizes, especially at sch80 and higher, seamless is preferred to ERW because it is difficult to assure the quality of the weld seam in a way some people find acceptable. I'm not knowledgeable in this regard- I'm merely parroting what others have previously said here, who are knowledgeable.

In 20 years we've never seen a single through-wall defect on carbon steel ERW nor have we ever experienced a weld seam failure, so that gives me reasonable comfort that the stuff isn't garbage. That said, I've seen enough examples of carbon steel A53 ERW pipe from China with nasty failures that we currently exclude all ERW from China. Not fair of course, to exclude a whole country's output based on a few mills' failures, but it's not possible for us to pick a mill and use only their output- we have to take what our distributors sell us, so excluding Chinese ERW throws out the good Chinese material with the bad. We don't exclude Chinese stainless ERW.

In our experience, ERW carbon steel or stainless doesn't cut or thread or roll-groove any differently than seamless, so I wouldn't pay the premium for seamless for that reason. Seamless tends to have a much inferior ID surface roughness and looser dimensional tolerances in general, so from a pure fabrication perspective we find ERW easier to deal with.

As to the OP's inquiry, I have no idea- we don't do anything with pipelines. In B31.3 normal fluid service, both materials are permitted, subject to proper design.

 

[zdas04]

In B31.3 ERW has a lower design factor than seamless. In B31.8 they are the same. The difference goes back to 1985. Before US Steel built the Fairfield, VA plant, US Oil Country Tubular Goods (OCTG) products were crap (frequent through-pipe defects, and when the girth-weld x-rays included the longitudinal weld the whole thing got rejected) and the ERW (which used the same processes as the failed spiral wound pipe) was the worst. Between 1980 and 1985 all of the major Oil & Gas producers looked to Japan, Germany, and Italy for pipe. At that time ERW from the European and Asian mills was almost as reliable as seamless (and in sizes bigger than 12-inch ovality and wall thickness consistency were a problem with seamless so the ERW was preferred in BigInch sizes).

When Fairfield opened, the game changed. OCTG from that plant was the best in the world and the ERW above 6-inch was superior to any seamless made in the world. The rest of the producers either upped the quality of their product or went out of business. B31.3 still has some residual holdover from the dark days. B31.8 has exorcised those memories.

Today I use RTP below 8-inch, and ERW above 8-inch. It has been 10 years since I had to make a steel-pipe decision on 6-inch and I used ERW for that job (it was a cost and availability thing, not a performance thing).

One observation about ERW--most of the MIC failures I've seen in gathering system have been in situations where the longitudinal weld was on the bottom of the pipe with water standing in a sag. My hypothesis is that the microbe's offal is especially corrosive in the HAZ of the longitudinal weld. I don't know why it doesn't seem worse at girth welds, but it doesn't seem to. On ERW jobs I always carry a sample of failed pipe to the kick off meeting and show the pits in the HAZ and ask everyone to try to keep the longitudinal welds off the bottom of the pipe (especially in field bends).

David Simpson, PE
MuleShoe Engineering

In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. —Galileo Galilei, Italian Physicist

 

[engresague]

thank you all for your help

 

[bimr]

US Steel is in Alabama, not Virginia.Made US Steel:
• first steel pipe in the U.S.
• Introduced welded casing prior to 1913
• Introduced seamless drill pipe prior to 1913
• Introduced seamless casing in 1924

http://www.steel.org/Making Steel/~...elPlant_NorthAmerica_HypocycloidVersion6.ashx

Having worked in a Youngstown Sheet & Tube mill, my recollection is a little different than that posed above. I trust that the steel mill history put out by the API is probably more factual than what has been described above:

http://www.api.org/oil-and-natural-...natural-gas/ppts/other-files/decadefinal.ashx

"Some safety codes and regulatory agencies also assign a longitudinal joint factor to account for weld efficiency. The more common are 0.85 for ER W pipe and 0.60 for CW pipe. Seamless pipe enjoys a joint factor of 1.00. This means that some designers consider ER W pipe as 85 percent as efficient as seamless pipe and CW pipe only 60 percent as efficient for the same application. Therefore, for a given application, ER W pipe would require a heavier wall than seamless pipe, and CW pipe, in turn, would require a heavier wall than ER W pipe."

http://usstubular.com/resources/lib...teel-tubular-products-standard-and-line-pipe/

Here is a specification for steel pipe:

http://www.indps.com/pdfs/Specification_for_Steel_Pipe.pdf

There is a never-ending debate whether seamless is better than welded. The arguments typically center on structural integrity and corrosion resistance of the weld, severity of the intended service, NDT and inspection requirements and delivery time. In reality, both production methods can provide the necessary quality and service life, corrosion resistance and reliability. Generally welded tubes are less expensive, have narrower tolerances, thinner nominal wall thickness, better concentricity (outer/inner diameter OD/ID), higher internal surface quality and are often chosen since they can be produced in longer lengths with larger diameters. Seamless tubes are needed where heavy wall thickness is combined with small diameters making forming of plate or strip complicated and where the standard specifically specifies seamless.

 

[zdas04]

It has been a long time since I had any direct responsibilities with regard to OCTG. I obviously mis-remembered the state. Since at the time I'd never been east of the Mississippi except for boot camp in Florida, you might understand how all of those states ran together in my mind.

I have never worked in a steel mill. From 1980 to 1989 I worked very closely with Amoco's purchasing department for tubulars, pipe, and steel. From 1983-1985 pipe made in the U.S. was inferior and we paid significant premiums to get it from Europe and Asia. The purchasing guys said that "when Fairfield opened ...", I assumed that that meant a new plant, but it could have been a new furnace, or a renovation of an existing facility. After 1985 we preferentially purchased U.S. steel products and the rejected joint occurrence went to basically zero.

David Simpson, PE
MuleShoe Engineering

In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. —Galileo Galilei, Italian Physicist

 

[blacksmith37]

I wrote the Amoco specs for OCTG and line pipe in '80s and 90's (and worked on API com 5).Some good comments, some wrong. Very briefly; It is much easier to screw-up ERW than smls. And all significant flaws can't be found in ERW by NDE. eg. weld zone not fully recrystallized, slit sklep causing outbent fiber flow ( dectable in lab but not on production line NDE ).

 

[blacksmith37]

I think I was too brief: Both poor heat treatment and fiber flow cause brittle failure of the weld seam. There is a more important factor; If the user audits the mill and has inspectors present during manufacture, ERW can be excellent . Amoco used more of it than any other majors (20 years ago). But if you are going to a pipe distributer for a truckload, you don't know the quality of the ERW; It may even be rejects from a large order. So for small projects, I recommend seamless.
As for Fairfield, the oil companies were very disappointed in it, especially since they had funded it. Fairfield chose not to make couplings and couplings are the weak link of every casing string, so it was same old crap for coupling stock.
And I must say any comments on stainless ERW are wrong. The steel must be ferromagnetic for ERW, so austenitics can not be welded with ERW.

 

[zdas04]

I sure saw a lot of Fairfield pipe come into the drilling program starting in 1986. I don't remember a lot of disappointment and we kept using it over Japanese and German pipe (I managed the inventory system and spent a lot of my time working with end users and purchasing on how physical-world movements of pipe were reflected in the inventory and I heard a lot of non-system complaints--in addition to the complaints about the system).

I've never been involved in deployment of use of Stainless in upstream operations so I don't have any opinions on that subject.

David Simpson, PE
MuleShoe Engineering

In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. —Galileo Galilei, Italian Physicist

 

[moltenmetal]

Sorry for the imprecise use of terminology in my previous post. The austenitic isn't ERW- the seam is welded by other means.

 

[blacksmith37]

I am sure Amoco and other oils used Fairfield for ordinary grades- J , K, and N, and X52 (high tonnage usage) ; Most majors had a commitment to buy specific tonnages. It was a "buy American " effort by the oil co. The interesting thing is USX would ship imported pipe in place of Fairfield pipe, depending on the market.

 

[weldstan]

There was a previous query some time ago where Chinese A-53 B ERW pipe was used in an off shore application. It burst upon hydrostatic testing below 150 psig. So beware of the source.

There have been many more than one failure in the long seam of ERW pipe manufactured before the USX mill was on line and there are other mills making ERW pipe throughout our global economy. There are many ways to produce ERW pipe with poor performance including: steel making (introducing long stringer type nonmetallic inclusions), improper trimming, inadequate force, introduced contaminants, electrical issues, and poor to useless NDE methods and I saw plenty of them during my initial tenure as a metallurgist in an ERW mill in the late 60's and early 70s. And I fully understand that steel making has made great strides during the past 30 years, but not everywhere.