×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Pcm of piping material is higher Pcm of PQR qualified

Pcm of piping material is higher Pcm of PQR qualified

Pcm of piping material is higher Pcm of PQR qualified

(OP)
hello everyone
I have one question is: when I qualify a PQR carbon steel A106 Gr.B pipe to pipe, the Pcm calculated in mill certificate is 0.245%. however, Pcm carbon (A106Gr.B) piping material show on mill certificate for fabrication in my project is 0.255%, what we can do in this case.

RE: Pcm of piping material is higher Pcm of PQR qualified

What fabrication code are you using?

Pcm carbon equivalency typically does not apply in piping codes such as ASME B31.3

RE: Pcm of piping material is higher Pcm of PQR qualified

(OP)
DVWE,

Code applicable is ASME B31.3, 2014. but client's specification required Pcm allowed plus 0.02%

RE: Pcm of piping material is higher Pcm of PQR qualified

If your client allows the Pcm qualified plus 0.02%, you should be qualified up to 0.265%. Typically you would want to specify this maximum on your WPS, and purchase all materials to be welded accordingly. The pipe with 0.255% Pcm should be fine if this is the case.

RE: Pcm of piping material is higher Pcm of PQR qualified

(OP)
CWEng,
my project is urgently, If I do a new qualify PQR with Pcm highest, it mean that project will delay. 35% purchase materials higher WPS. almost my project is CS (P nos 1).
pls advise how to do, new PQR qualify or other better solution for this case.
Clients specication is not specify for carbon equivalent applied material typical, I think Pcm only applied for 0.11%C and low alloy steel up to hight alloy

RE: Pcm of piping material is higher Pcm of PQR qualified

Sorry, I'm really not sure what your last post is saying.

RE: Pcm of piping material is higher Pcm of PQR qualified

Quote:

but client's specification required Pcm allowed plus 0.02%

Pcm allowed by your client? Or Pcm qualified in the PQR?

RE: Pcm of piping material is higher Pcm of PQR qualified

quatle,
Is your clients specification in English ?
If so copy and paste or type the exact wording of the clients requirements - you will get a much quicker response.
Half of the questions we see on this forum are from people who don't understand the requirement as written or have misinterpreted the requirement.
If your first language is not English it can sometimes be hard to fully understand client requirements if written in English (in some cases you cannot understand them even if English is your first language. LOL !!)
Cheers,
DD

RE: Pcm of piping material is higher Pcm of PQR qualified

(OP)
DekDee

thank you for your support, English is my second language.

we can see the section of clients specification as below:

4.2. Essential Variables
4.2.1. Essential variables shall be those required by the applicable industry code (e.g., API 1104, ASME Section IX or AWS D1.1) and the additional variables in TABLE 1. Any deviation from these variables shall require a new weld procedure be qualified. All essential variable tolerances listed as percentage variations apply to the actual qualified mean values recorded for each pass.
4.2.2. Test pieces for welding procedure qualifications shall be in accordance with the referencing COMPANY specification and industry standard.
4.2.3. Test pieces for procedure qualification of carbon steel shall be selected from the higher range of carbon equivalents. All qualified procedures are based upon the carbon equivalent (Pcm) of the parent metal being defined as:

Pcm = C + Si/30 + (Mn+Cu+Cr)/20 + Ni/60 + Mo/15 + V/10 + 5B
4.2.4. Procedures shall be qualified for welding production materials with a Pcm up to and including 0.02% higher than the qualification test material. Heat / ladle analysis may be used if approved by COMPANY when product analysis is not reported. Use of higher Pcm steels will require a new welding procedure qualification.

RE: Pcm of piping material is higher Pcm of PQR qualified

quatle,
See the first response from CWEng.
Your 0.245% qualified plus the 0.02% allowed by the specification means you are all OK with fabrication material up to 0.265%,
Cheers,
DD

RE: Pcm of piping material is higher Pcm of PQR qualified

Agree with DekDee and CWEng.

RE: Pcm of piping material is higher Pcm of PQR qualified

(OP)
DekDee and CWEng

I'm sorry for put wrong the acceptable table in my exel summary file. re-correct WPS Pcm is 0.22% and purchase materials is 0.56% sample. almost the material are Flange and fitting.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources