inspection instrument

Date 12-03-2009 07:42

I doubt you will find any portable equipment.
To the best of my knowledge it can only be done by taking a sample of the molten metal and determine the temperature at different phase changes.

3.2

By Richman (**)

Date 12-03-2009 08:37

I know also it can be done thru impact testing. But is there any other method as what I said and 3.2 in checking LTCS materials or not?

By 3.2 Inspector (***)

Date 12-03-2009 09:04

I just looked at your previous questions...
The piping is already installed, right?

If so, the only way I can think of is to verify charge numbers of each component :)
Stringent material and heat number transer procedures should have been establised before the project started.

When you do a line walk prior to hydro testing, you must be able to see all charge numbers on each piece of pipe and fitting.
In case of no charge number, it is a cut out.
Inspections at regular intervals should have been made during the construction in order to assure that the procedures was followed.

3.2

By Richman (**)

Date 12-03-2009 13:44

You are right 3.2 heat number didn't transfer during construction and fabrication and we have hard time now verifying those piping works by sub/contractor.The problem is the sub/contractor says and insisting they are LTCS materials even though no color codes or heat number written in the pipe. And that's very hard for us to prove they are wrong. As inspector what is the best thing to do to convince the sub/contractor that we have doubt on the materials they used

By 3.2 Inspector (***)

Date 12-03-2009 13:48

EPIC FAIL!

By Lawrence (*****)

Date 12-03-2009 14:59 Edited 12-03-2009 15:03

Rich,

I may be looking at it too simply.

But if the data did not transfer and there is no record proving the correct materials were used, It may be wise to process non-conformance doccumentation of what you are seeing and just allow the chain of command to deal.

If you are the inspector you don't need to convince anybody of anything (under most circumstances) you are simply inspecting and noting on your reports whether the work conforms or does not conform.

It might be easier for people with greater authority to compel the subcontractor to *prove* the materials are LTCS.

I realize that in the real world we live in, that some compromise will likely be struck.. But it would be wise for somebody else higher up the chain to make the call on it, senior engineer or some other high level authority.

If management is just willing to take their word for it.. Let me know... I have a big pile of gold bars in my scrap bin :)

By 3.2 Inspector (***)

Date 12-03-2009 17:08

It seems to me that Richman is the owner/user, maybe client's rep. of a new LNG plant, or a new unit within an existing plant.
I would rate most piping within such a plant as "critical"

The contractor has to follow the design code and client's spec. of such a plant
I doubt very much that it is not written anywhere that full traceabillity is required.

All fittings should have the charge number stamped, that should be checked during line walk prior to hydro testing. The same goes for atleast some of the pipes.
For the remaining pipes (without charge) I would demand that the contractor cut out some samples, starting with the most critical lines.
In case of wrong materials used, I would demand an increase in samples checked, if to many samples turns out "wrong" I would refuse to accept the unit.

3.2

By Richman (**)

Date 12-04-2009 09:12 Edited 12-04-2009 09:14

I'm the clients rep for new LNG project. The things is many of the pipes or spools and fittings for LTCS lines is already painted and we have a hard time verifying the spools and fittings is correct or not, that is why I'm asking what type of instrument to use in checking the LTCS materials.

By supermoto (***)

Date 12-03-2009 13:51

Couldn't you use a a rockwell or brinell hardness tester, I have seen portable ones. Not sure how it would work on pipe.

By joe pirie (***)

Date 12-03-2009 15:55

can the contractor provide mill certs from the supplier. purchase orders that would show the size and grade of pipe used.
I've never seen new pipe that didn't have some kind of id marking. Did they paint or insulate over it. Is this critical pipeing ?
In the structural world if we can't identify a piece of material or the heat #'s don't match mill reports the contractor has to
cut out a test specimin from material and send it to the lab. I've seen some sleaze ball contractors try to get away with
some unbelievable ****. I agree with the other inspector write the ncr's anfd let upper management fight it out

By Superflux (****)

Date 12-03-2009 17:21

Try out these Oxford Analysers for the carbon content.

Acuren and other NDT firms usually have Niton analysers for the metals content.

http://www.oxinst.com/products/oes/mobile-portable/arc-met8000/Pages/arc-met8000.aspx

By 3.2 Inspector (***)

Date 12-03-2009 17:33

Hmmmm

Taken from their website:

Ideal for ferrous and non-ferrous metals.
Low alloy steels, Stainless steels, Tool steels, Low alloy (white) cast iron, Aluminum alloys, Titanium alloys, Nickel alloys, Cobalt alloys, Copper alloys, Zinc alloys, Magnesium alloys...Ask us about your specific analysis requirement by simply clicking on the Contact us now option box above.

Why would they not mention CS?

3.2

By jrw159

Date 12-03-2009 17:43

Ummm... they did.

"Ideal for ferrous and non-ferrous metals.

jrw159

By 3.2 Inspector (***)

Date 12-03-2009 17:50

uhm....sure?

Ideal for ferrous and non-ferrous metals. <----COULD THIS BE A HEADLINE????
Low alloy steels, Stainless steels, Tool steels, Low alloy (white) cast iron, Aluminum alloys, Titanium alloys, Nickel alloys, Cobalt alloys, Copper alloys, Zinc alloys, Magnesium alloys...Ask us about your specific analysis requirement by simply clicking on the Contact us now option box above.

They DO NOT specify CS, they claim they can measure C in LOW ALLOY STEELS.
I am sure you can tell the difference between CS and LOW ALLOY STEELS.....right?

3.2

By jrw159

Date 12-03-2009 17:59

I think you are missing the point. CS falls into the "ferrous metal" category, does it not?

jrw159

By 3.2 Inspector (***)

Date 12-03-2009 18:03

LOL,
Then why do they specify it just below?

3.2

By jrw159

Date 12-03-2009 18:09

I suppose just to throw off those that are easily confused.

jrw159

By ssbn727 (*****)

Date 12-03-2009 17:56

I agree... Why cut out blindly when one can analyze the material chemical composition instead! ;) Then if it is indeed the wrong material, cut outs can be performed with confidence as opposed to blindly cutting out samples that would require avoidable rework should the material be found to be of the correct composition resulting in a significant waste of scheduling extra man hours and time for repairs... It's a better way to go by using the analyzers first! ;) A much better risk assessment as well!

Respectfully,
Henry

By 3.2 Inspector (***)

Date 12-03-2009 18:02

Not cut out blindly, I just dont think there is any non-destructive analyzers which can dertermine which grade of carbon steel it is.

3.2

By jrw159

Date 12-03-2009 18:10

http://www.dciinc.com/literature/brochures/PMI_FE04_Bulletin.pdf

By 3.2 Inspector (***)

Date 12-03-2009 18:18

Thanks for link, which leads to a contractor who makes SS tanks :) (hint: SS is a highly alloyed steel)

3.2

By jrw159

Date 12-03-2009 18:28

Here is another one. Just call them they will tell you the same thing. No sense in arguing with you over it.

http://atlas-inspection.com/blog/rental/rent-niton-hand-held-xrf-%E2%80%93-pmi-gun/

It will indeed positively identify all steel.

jrw159

By ssbn727 (*****)

Date 12-03-2009 18:14

It doesn't have to.. All it does is give one the chemical composition, and then all one needs to do is to compare what has been analyzed with what is in the required grade of carbon steel, and one can easily back check to P.O.'s to any attached MTR's... Now if these are not available because of poor record keeping or whatever other ridiculous reason, then the grade of carbon steel that has been listed in the contract doc's is to be the referenced grade to compare... The chemical compositions are easily accessible for the grade listed through a variety of methods, and I'll just say that this is done quite often in the states in order to avoid cutting out material without doing an on site chemical analysis via PMI beforehand. (Positive Metal Identification) Especially on critical piping I might add.;)

respectfully,
Henry

By 3.2 Inspector (***)

Date 12-03-2009 18:17

Henry,

I am fully aware of what PMI is.
PMI is done worldwide every day - EXCEPT on plain CS.

3.2

By jrw159

Date 12-03-2009 18:31

It may not BE done every day on CS but it sure CAN be done with a PMI gun.

jrw159

By 3.2 Inspector (***)

Date 12-03-2009 18:34

If I may ask,
Have you ever done an XRF analyzis to check which grade of CS you are dealing with?

3.2

By jrw159

Date 12-03-2009 18:38

No I have not had the need to but that is not the point. The point is that if the need is there it CAN BE DONE!!

Now you can be as contrary and argumentative as you like but it will never change the FACT that it CAN BE DONE.

Done, much like I am done with you. :-)

jrw159

By 3.2 Inspector (***)

Date 12-03-2009 18:50

Understand this...

When you buy a XRF Analyzer, part of the periodic chart is inclosed.
It CLEARLY shows that you can't measure the carbon content in order to determine which grade you have - solely based on carbon content.

3.2

By ssbn727 (*****)

Date 12-03-2009 18:34 Edited 12-03-2009 18:48

Well according to these folks it is:

http://www.tcreng.com/products/pmi-instruments-for-sale.shtml

http://www.innovx.com/applications/metalalloy/pmi

And an article in the January 2005 Winter edition of Inspection Trends as well:

http://www.sanama.hr/Administration/_Upload/Documents/Inspection_Trends_012005_web.pdf

http://www.tcr-atsco.com/services-tcr-atsco/positive-material-identification.shtml

http://www.pipingequipment.com/Bulletin/Bulletin%2000-7.pdf

Here's another one from Oxford:

http://www.oxinst.com/products/oes/mobile-portable/pmi-master-pro/Pages/pmi-master-pro.aspx

And finally, an oldie, but a goodie... Click "View document" to view the .pdf:

http://www.osti.gov/bridge/purl.cover.jsp;jsessionid=3A20578967F2EE39F546872BA61CC844?purl=/105096-11bL1t/webviewable/

I have also witnessed being performed when this type of instrument first started being used widespread in the power industry as well... So I know that it's done quite frequently not just in the states, but all over the world as well... In fact, this method was used to indicate exactly where the locations of the incorrect filler metal was deposited on those nuke subs being built @ Northrop Grumman in Newport News, VA, and they determined that the repair could be easily performed in substantially less time than originally estimated thanks to the use of PMI! They, meaning the USN also determined that the structural integrity of the components were NOT compromised as well.

Respectfully,
Henry

By 3.2 Inspector (***)

Date 12-03-2009 18:48

More links :)

Except the one from Oxford, all the other mention ALLOY elements.
Obiously you can measure on a CS steel, and the XRF Analyzer will tell you it is a carbon steel, but not the exact grade.

3.2

By ssbn727 (*****)

Date 12-03-2009 18:49

No, but it will help you determine the exact grade via comparison of the chemical composition which it does in fact give you rather precisely I might add.:)

Respectfully,
Henry

By 3.2 Inspector (***)

Date 12-03-2009 18:58 Edited 12-03-2009 19:00

But not precise enough.
The company I work for also does PMI - the guy who did it reported a certain grade of carbon steel, can't remeber which one.....all with good intentions.
Hell broke loose, we had a small seminar with the leading XRF Analyzer producer in Europe.

He clearly told us - along with showing us the chart, which tells you that you cant dertermine which grade of CS it is. By the way it works, it NEVER will be able to measure it.

3.2

EDIT: It might give you a 95% match for a given grade, but that is based on the other elements which is detected.

By ssbn727 (*****)

Date 12-03-2009 19:11

If you read page 15 in the AWS Inspection Trends article, it does in fact state that the XRF method is limited in assisting to determine up to 20-25 grades of carbon steels that are usually found in a petro-chemical or process type of environment... Look! there's no disagreement that the Oxford equipment method does do a better job than the FP-RPMI's can, and a competent testing agency would also be able to give the proper consulting to determine which would be the best technology to use in specific situations.

The point is that PMI if properly understood and applied in the cxorrect manner will be far more useful in determining whether or not the proper materials were used in a given situation or not without having to cutout sections without any proof whatsoever that the material is indeed incorrect beforehand.

Respectfully,
Henry

By 3.2 Inspector (***)

Date 12-03-2009 19:30

Henry,

XRF Analyzers are very limited AND highly inacurate. You can measure the same material twice, and get 2 different results.....do it a third time and you maybe get a third result.
I really don't think that it can be determined if the material is for low or high temperature applications, without a destructive test, ie cut out a sample of each pipe.

I recently dealt with a P91 flange which had low hardness, one of the leading metallurgical companys in europe was brought in, they suspected low carbon content was the reason why full martensitic structure was not present, they asked for permission to cut out a small piece of the flange in order to take it to the lab for further investigations. The contractor, which at that point still thought they had a chance to save the flange, refused the destructive test.
Later the flange was rejected due to "uncertain non martensitic structure"

They explained again and again that in order to do a PROPER investigation of the carbon content, a sample had to be cut out......they both had a Phd. in metallurgi.

In regards to OP's problem, it is not only a matter of CS grade, without correctly transfered heat numbers you can't be sure of the materials origin, has the correct test been done, etc, etc...Which in some parts in the world is rejectable in the first place.

3.2

By ssbn727 (*****)

Date 12-03-2009 19:56 Edited 12-03-2009 20:01

I disagree with your conclusion since you have not offered any proof besides what you claim and unless you can offer empirical proof, then everything that you have posted is based soley on heresay... The Manufacturers of the XRF instruments method of PMI do offer empirical proof that their instruments are accurate as well as have certain limitations up front... The OES (Optical Emmission Spectroscopy) do the same and are better suited for the OP's application. just because there was a problem with one specific situation does not mean that PMI doesn't work the way it is supposed to when used by competent and well trained professional otherwise there would be a world wide warning to all of the inspection agency's stating otherwise so, that is the primary reason why I disagree with your assumption... It's okay that we disagree, because nobody always agrees with each other in here anyhow! ;)

Besides, it's ultimately the call of the EOR like Kip mentioned in his post which really clarifes this whole discussion in a nutshell. ;)

Respectfully,
Henry

By 3.2 Inspector (***)

Date 12-03-2009 20:32

Henry,
You seem very experienced in surfing the internet.
Now go and surf for the limitations of XRF Analyzers, or even better, use the equipment yourself.
I will give you a hint, it is limited in the number of elements it can measure. You will not find a single XRF which can detect carbon :) or anything below atom #22 as the x-rays get absorbed by air traveling to the detector head.

To be honest, I was not aware that OES was portable, I have never seen or heard about it being on site.
I would still like to see proof that it can tell whether it's CS for low or elevated temperature applications. I am still not convinced it can be used in this particular case.
I still hold on to my first statement, to have sample pieces cut out for mechanical tests.

I hope the OP's company spend the $$$$ to make a EOS measurement. :) and tell us the result.

3.2

By ssbn727 (*****)

Date 12-03-2009 20:37 Edited 12-03-2009 20:41

No need to 3.? I already pointed out the limitations to both you as well as anyone else interested, but then of course -you already knew that! So please do not spoil this rather good thread with anttempt to bait me into an argument with you that I already do not have, or will have with you - CAPECHE??? If not, then learn how to follow my posts better! ;)

Btw, the equipment can be rented at reasonable rates as well.

Henry

By 3.2 Inspector (***)

Date 12-03-2009 20:45

I did follow your posts, I just got confused because you have posted several links to XRF Analyzers, when the debate was how to measure carbon :)

3.2

By ssbn727 (*****)

Date 12-03-2009 22:25

Well then here are some more manufacturers and an inspection services company which offers OES technology for portable PMI:

http://www.gnr.it/edp.htm

http://www.spectrolab.co.uk/pages/esaport/pdf/esaport.pdf

These guys do both XRF as well as OES quite often:

http://www.petrochemintl.com/industry/petrochem/services/pmi.cfm

http://www.spectro.com/pages/e/p010106.htm

http://www.spectro.com/pages/e/p010101.htm

There are more out there, but I thought that if I stop here with just these, then one might not be too overwhelmed,or confused with all of the data to digest. :)

Respectfully,
Henry

By 3.2 Inspector (***)

Date 12-03-2009 22:27

easy to digest, but difficult to interpret.
Dont send links to XRF, when we are talking about carbon - problem solved.

3.2

By ssbn727 (*****)

Date 12-03-2009 22:46

Okay then scroll down Edit: up from this post on this very page a little bit, and you'll see the links I posted for some of the manufacturers of portable OES PMI equipment as well as one of the many inspection services companies that offer both services... There are also quite a few firms the offer rentals of both types of portable PMI instruments as well so the technology is NOT restrictive in getting access to it for field work.

Btw, I have one of those USB type wireless modems that enable me to stay online wherever I want to be just about, except of let's say some places in deep rural areas where even there sometimes the signal strength can sometime be strong enough to stay online for quite some time... I believe only once when I was in the mountains of West Virginia did I have some disruptions in service... So yes indeed I do know how to surf on the internet... Doesn't everybody??? ;) Now don't forget to check out the links for the portable OES equipment offerings - CAPECHE??? They will certainly expand your awareness and knowledge base of this technology further which I'm always more than happy to help anyone to achieve! ;)

Respectfully,
Henry

By raptor34 (**)

Date 12-09-2009 03:17

I have done PMI on cs.

By Superflux (****)

Date 12-03-2009 18:05

Exxon called in one of these Oxford contractors to verify a peroxide system we installed (316 S/S). We had 100% traceability on everything. P/O and pipe delivered from suppliers was down to the inch. They didn't trust anyone!

By 3.2 Inspector (***)

Date 12-03-2009 18:09

(316 S/S).

Which is a high alloy steel :)

3.2

By Superflux (****)

Date 12-03-2009 18:26 Edited 12-03-2009 18:31

I hope the O.P. keeps us updated on the resolution of this issue.

By 3.2 Inspector (***)

Date 12-03-2009 18:29

Thar XRF Analyzers can be used on high alloy steel grades.

3.2

By Bill M

Date 12-03-2009 18:49

So the way I understand it - there are two different methods discussed here.

The XRF Method is hand held and uses an x-ray source for the x-ray florescence analyzing method. This method cannot display carbon content, but can show alloys such as Mn, Cr, Ni, Mo, etc.

The Oxford type is still somewhat portable, but actually burns a tiny sample and uses the optical emission spectrometer method. This method can do carbon content.

Am I correct?

By 3.2 Inspector (***)

Date 12-03-2009 18:52

The way I read the Oxford document - yes
An XRF Analyzer never has or never will be able to do it.

3.2

By kipman

Date 12-03-2009 19:27

I am exposed to PMI very frequently. One of the limitations of all of the PMI methods (at least the ones I've used) is that they cannot tell you what material specification (if any) was used to manufacture the material. Some methods can indeed measure carbon content. So with the right choice of method you may get a fairly accurate measure of the actual total elemental content of the material in question.

With this information you may be able (by process of elimination) to determine which material specs a certain material does not comply with. If by process of elimination you arrive at a place where there is only one published material specification with elemental ranges that match the actual elemental content of the material under test, then it may be that the material under test was indeed manufactured in accordance with that spec. There is usually no way to know this with 100% confidence however, as most material specs also require other characteristics besides elemental content (such as heat treatment, rolling conditions, etc, etc).

3.2 was right on the money regarding loss of traceability - you are now in an ugly situation, and of that there is no doubt. However, with the information on elemental content the Engineer of Record may be in a better position to make an engineering judgment about what to do now that traceability has been lost. As Henry noted, it may be possible to polish this particular turd and accept as is - that will be up to the EOR. Either way, it's an expensive lesson. Don't lose traceability in the future.
Mankenberg