Inspection of repairs 3

[apiguy]

I would like to present the following question to everyone:

Background :
I have a new piping system with a design of 2 psi vacuum. The material is SA312 type 254 smo. First round of x-rays failed. First repair complete. Re- xray fail.

Question:
The weld will be repaired with me observing everything. The old weld will be removed completely. May I follow the principles of an In-process Examination including dye penetrant testing of the root, hot pass and cap in lieu of radiography?

Please advise..... Richard Schram
Mechanical Integrity Specialist
Pharmacia Global Supply Arecibo-P. Rico
rschram@pharmacia.com

 

[PAN]

In my opinion PT for each layer is good. RT is still required...The result of RT tend to be passed if you can strictly inspect for all layers.

P.S. : Hope the welder qualification is not the problem...

 

[khalid123]

dear sir
i would like to now the proucduer of testing

 

[laphroaig]

Hi
what kind of welding errors is it? what does the x-ray reports say?
You must know what kind of errors there are in the weld to prevent the same happens again.
for example lack of fusion could be a result of low energy etc.

JH

 

[apiguy]

khaild123 :

I would rather not disclose the name of the Company performing the NDE services for obvious reasons as listed below:

laphroaig:

I cannot rely on the reader sheets. I am experienced in film interpretation myself and there is quite a difference in opinion over the defects seen. (This should open up a big can-o-worms)I have had access to the root visually and have rejected several welds for longitudinal cracking VISUALLY. The reader sheets report " Incomplete Penetration " or "lack of fusion" as the culprit. On another welding related forum, there is a posting regarding welds of this same material having what appears to be a black line running down the center of the weld that is not IP,LOF or a crack. They seem to think that some sort of oxide layer may be forming in the weld during welding. I am waiting to see what becomes of more research on that subject.
I'll keep everyone posted.... Richard Schram
Mechanical Integrity Specialist
Pharmacia Global Supply Arecibo-P. Rico
rschram@pharmacia.com

 

[Olgreen]

Can you specify the pipe thickness and the welding process?

 

[apiguy]

olgreen,

The material in question is sch 10. SA312 type 254 SMO with the GTAW process. Richard Schram
Mechanical Integrity Specialist
Pharmacia Global Supply Arecibo-P. Rico
rschram@pharmacia.com

 

[nassaj]

I Would like to W.P.S & SCH? & N.P.S AND OTHER INFORMATION ABOUT MY ADDRES ADNASSAJ@YAHOO.COM

 

[apiguy]

nassaj-

I don't understand the question or comment...please revise. Richard Schram
Mechanical Integrity Specialist
Pharmacia Global Supply Arecibo-P. Rico
rschram@pharmacia.com

 

[laphroaig]

It could be an idea to check type and flow of the gasshield on rootside.
Regards
JH

 

[moseley]

API GUY,
I have ran into the same "differences in opinion" and this is never fun! My solution was to inspect the whole weld, beginning with the root pass and then every pass there after. The result was that the NDE company and the Client were far off base of what they seen on radiography. What I seen was that after the root pass, we increased the backing gas flow and it prevented the line that you refer to. Also as you know this schedule material when welded with improper heat input will "egg" and give this indication. So LPT of every pass will not help, maybe some good ol' fashion sense with the NDE company will solve this problem.