ERW or Seamless-How to identify?

I take it by ERW you mean Electric Resistance Weld?

Just to start people off....

There are three common types of pipe available, straight welded where a thin stip of metal is folded and welded along its length parralell to the pipe centre, Spiral wound where as the name suggest a strip is wound around a form and the edges welded to form a spiral aound the pipe circumference and seamless which is formed from solid bar which is upset by twisting rollers to creat a hole in the core, it is then forced along a mandrel form to produce tube with no weld and often a work hardened interior surface.

Both welded types leave a visible weld area even after polishing or annealing. However you can also pick them up by UV examination of the grain structure will show a distinct difference in the weld zone. Annealing will make it harder to see but it is very difficult to destroy completely, Particularly on the inside surface! It will reappear after bending too!

Welded pipe also often a has a ridge on the inside which you can find deep in the pipe by rolling a tight fitting ball down the length. Where the ridge hasn't been polished off the ball will stick. Of course the pipe needs to be straight and free of dents for this to work and it isn't good with spiral welded pipe as the ball can roll around the weld.

Hi...as long as the pipes are on the ground it's easy to see and feel the seam by examining the inner surface.

Ha, ha..but i remember a prank when some workers in a steel plant welded a solid 38mm bar at 40meters height in between a Dn32 steam tracer line. My collegue had a real tough time finding out the reason as to why the steam was'nt passing through!!

It is only possible when the pipe ends are open. You can do a Macro-test.

Put H2So4 or HNo3 acid on the edges.

If it is welded, it will show the weld boundries. If not welded it will not show edges.

To identify that a pipe supplied is seamless or ERW, Simply read the stencil on the side of the pipe

If it is ASTM A53, Type S means seamless.

Type F is furnace but welded,

Type E is Electrical resist welded.

Thats how.

Sometimes, a simple answer is appropriate.

milo

Hello Milo,

how are you?

Thanks for the simple explanation. Think the OP is on holiday!

Why could they not have search for it like I did, trying to find and explain and show what code goes with which pipe type? You have to wonder some times why a search is not done using the same phrase they sent in to CR4? Weird.

Take care...............

Hi Babybear.

Perhaps they feel like this site is more authoritative.

The difference between a response from one of us and just finding facts on the web is that perhaps we add "context." And lessons of experience. And at least traceability, if not authority by our screen names.

So who wouldn't prefer a host to provide an answer as opposed to self serve?

Even mcDonalds drive through will hand you your order. as opposed to just finding your coffee sitting there.

Many of us provide additional information that provides "the rest of the story." so that's why I think folks might prefer to use CR4.

Best regards.

milo

Hello Milo,

very well put piece there! I do think as per your post for 'good' interesting and half-way informed threads, but I guess what I am trying to say is, they should try a search then come here perhaps for confirmation.

I am not trying to chase people away, but I would always do a search or searches first then come and ask "is this correct"? I do know people (friends) who search and they are only interested in THAT SEARCH for as long as it takes, and learn nothing and do not WANT to learn anything. Sorry for any insults here, but I call that a 'blond' search attitude........Well, I have to have a laugh sometimes!

I fully agree that we do add detail that may not be found elsewhere, especially, such as personal reference using the product or item. At least that way they will know what they are looking for is the correct thing?

I appreciate your post Milo, thank you.

"but I would always do a search or searches first then come and ask "is this correct"?"

This is the evidence of critical thinking.

milo

Hello Milo,

Is that a good or bad thing then?...................I feel a search coming here!

I have alway been criticised to this day for making certain are as right and correct.....nice looking (NOT ME!) as possible. Watching the 'P's and Q's, and dotting the 'i's'.

I did make my fair share of mistakes on this site when I first started, though I can still slip on a banana skin that is 'lack of knowledge'

From each, according to their abilitiies...

I don't think there is a singular "right way" ...

though if i could be as witty as a certain feline friend that would be cool.

trying to match what is provided to the level of the question seems to be an art.

There are many wrong ways of asking.

They ask without providing key information; They demand to be spoon fed the full five course dinner; having done no prep at all; and of course, not even knowing how to structure a question. The obvious homework "list types of circuirts and gve examples " comes to mind. or 'About windenergy" ... Huh? And of course the ones with an axe to grind, rather than just putting their facts out their to see how they fare.

But to me, seeing so many different ways of answering even the simplest of questions teaches me a lot about the miracle of communicating.

as in

"It s a Miracle we communicate at all!"

milo

Hello Milo,

You did it again. Not quite so concise. But you said what I think most people 'who do not know what they want' when asking a question, should think about before ever coming to the site.

It seems quite a few.........not good English but, what the hell, ........are reluctant to admit they know nout about their request. There is nothing wrong with that. But if we knew it, then perhaps we could phrase and choose a more appropriate reply?

The most frustrating ; the ones who ask a question and you hear nothing. If they took the time to look they could see it is as much a 'discussion' shop as a question and answer forum.

I will not mention anyone here, but a recent request asked what a synonym of 4 letters meant on a requested estimate I think. And that was that! Nothing more to the open forum, though they did leave a note that they were emailing one of the posters. As there was about 8 people trying to help, a reply and maybe some more details would have been the way to go. Just converse.

Courtesy would be nice?

Take care, and thanks for the reply.

Hello Milo, hope you are fine..................

GA to you sir for, pointing out what should have been known. If there is only about three ways of fabrication, don't have to look far really?

Take care...................

Good morning babybear.

Thanks for the positive feedback.

The limitation on my answer was that it was "us-centric" as it reflects US/ North American practice and standards. (ASTM)

But I have to think that products produced elsewhere have a similar marking scheme.

So I felt it appropriate to suggest a valid method based on my experience and the possibility that the product in question might have been to the ASTM spec. We shipped a lot of pipe overseas when I was at the pipemills.

When posters provide more complete information, then we can provide more focused answers. in absence of specifics, generalities lead the way.

Keep your powder dry...

milo

Hello Milo,

very much appreciate you explanation, and yes, I will keep my powder dry for sure!

The thing about not knowing, which often times means we have to guess what is going to be done and how and when, not to forget in which Continent if not country we are talking of?

Obviously there should be no free reign of emails and or personal address', but an 'automatic' note which may be should be mandatory, in a Profile as to which area they reside, would make the 'helping' we all try to do a lot easier?

Take care Milo................

Hey. Yes, the original poster was registered, and so below his avatar was a location called gurgaon. So i just looked it up and found out its india, heres a link to a daily photo blog from there.

http://gurgaondailyphotoblog.blogspot.com/

Like i said, in a global market, who knows where the products might have originated.

nice chatting. Now I know something more about india, too.

milo

Hello Milo,

Thank you for the blog. I have to sleep at the moment but will view it later with interest. Thanks once again.

Take care...................

Dear ashu278,

In ERW pipe you can easily identify seam of pipe even at the end of pipe.

Otherwise you can go for physically inspection, just roll your Pam over outer surface by doing this closely monitor the filling on your Pam if pipe is seamless than you will fill only smooth surface and if it is ERW than then you will fill some roughness on it at some particular area & that we called Seam.

This will also help you even the pipe is welded with fittings & impossible to see inside or pipe spool is installed or live pipe line on plant.

Good Luck,

Regards,

Rahul Patel.

Dear Mr.ashu278,

Inside the pipe you can find the welding trace at the seam.

DHAYANANDHAN.S