CSA Z662-15 Lamination in Pipe 2

[IHQ22]

Greetings all,

I have a question regarding lamination in a pipeline designed as per CSA Z662-15. I cannot find any reference to it in section 10 regarding imperfections.
The lamination in question was found during a recent UT inspection.

Can anyone enlight me on this?

Thanks!

Fred

 

[Dhurjati Sen]

Dear FredG2,

Is the pipe rolled from a plate? What is the diameter?

Google lamination in plates.

Regards

DHURJATI SEN

https://www.nace.org/people/dhurjatisen

 

[IHQ22]

Hi Dhurjati Sen,

The pipeline is 12 NPS Sch. 40 A53 pipe. Should it be considered a defect as per CSA Z662-15? It is not mentioned in the code in the defect section.

Thanks!

 

[LittleInch]

Lamination where?

weld edge or main body?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[IHQ22]

Hi LittleInch,

The spots where lamination was found are mainly on the main body of the pip but some of them are close to the weld edge.
The pipeline has been in operation for the last 40 years and carries fuel oil at relatively low working pressure.

Fred

 

[Dhurjati Sen]

Dear FredG2,

From the bits and pieces gathered, we know the following:

a) ASTM A 53 Sch. 40 12" pipe

b) Service: Fuel Oil

c) Age: 40 years

You should have furnished the above in your original post instead of focussing only on CSA Z662-15.

Anyway, if the pipe is seamless, then lamination is probably ruled out. Confirm it.

Could be a case of hydrogen ingress and blistering.

Carry out Ultrasonic Flaw Detection ( A, B & S scans) and review the result.

Regards.



DHURJATI SEN

https://www.nace.org/people/dhurjatisen

 

[IHQ22]

Dhurjati Sen,

Thank you for your help. I will follow your advice next time I post.

I reviewed the information I have and it seems that some spools are rolled and not seamless. If this is the case, I assume the material defaults in that region might be lamination? Do you have any insight on how hydrogen ingress and blistering or lamination should be treated? Cut and weld in a new spool section?

Again, thanks a lot for your help.

Fred

 

[dhengr]

FredG2:
The steel mills will often sell a 38” wide pl. with some small laminations in it, when they are well bounded, and within the mid-width and mid-thickness of the particular pl. Who defines ‘small’ and middle is another matter. They should not come to the surface or edge of the pl. This is fairly common (not unheard of), it just goes unnoticed, unless ASTM A53, or your spec. and P.O. specifically call out full UT inspection of the pls. and no laminations allowed. Then, the argument is, are they laminations or slag inclusions, which sometimes show up about the same on UT’ing. The argument goes that laminations usually do not cause many problems as long as they are parallel to the faces of the pl. and the primary stresses run parallel to both. They are a problem where primary stresses or residual stress in tension are perpendicular to the lamination and tend to pull it apart. And, they are a problem at unprotected edges, where you can see them and bitch about them, otherwise you go on your marry way, with few problems, and 40 years of service kinda proves this. It seems to me that, over the years, I’ve even fixed a few laminations at edges by gouging them out and welding them back up, although I’m not so sure many codes or AHJ would look kindly on that. They can be a problem in highly restrained joints and around welds and difficult detail geometry where you can have high primary and residual stresses in all three directions. I am not a defender of laminations or the mills selling you junk, but I’ve had these fights many times with different steel mills.

 

[Dhurjati Sen]

Dear FredG2,

1. No need to cut and weld as of now as we know that we are talking of pipes made from plates.

2. Carry out USFD if possible. Review the result.

3. Already you have carried out UT scanning, so repeat it, say after every six months. Compare the results.

4. Forget about hydrogen ingress etc. for the time being.

You have thanked me, now could you put a star?

Just kidding, but recognize the fact that how wonderful this website is and be thankful to its creators & moderators.

Regards.

DHURJATI SEN

https://www.nace.org/people/dhurjatisen

 

[IHQ22]

Dhurjati Sen,

Thank you for your detailed explanation!

Fred

 

[weldstan]

The pipe was most likely electric resistance welded and laminations in the pipe skelp were not uncommon 40 years ago. And ERW pipe was commonly used in pipe lines as you have described. You should only be concerned with laminations that could extend into the longitudinal seam which could be detrimental creating essentially a location of lack of fusion. Strictly speaking laminations in the body of the pipe will not be detrimental in your reported service.