ASTM A-106 Gr.B vs API 5L Gr.B

[Johawn]

Hi all,

After looked back all our client welding procedures, I found that
- Their PQR using API 5L Gr.B (P No.: S No.1; P Group No.: S Group No.1)as Base Metal.
- and their WPS using base metal:
+ P No.: S No.1; P Group No.: S Group No.1; OR
+ API 5L Gr.B or equivalent;

Applied to our project using ASTM A-106 Gr.B.

I informed to them that that welding procedure can not apply to our project as per QW.420.2 ASME IX 2007 edition.

This is my explanation:
- API 5L Gr.B only consider as Base Metal has S No.1 and S Group No. 1 as per ASME IX 2007 edition.
- ASTM A-106 Gr.B can consider as ASME SA-106 Gr.B (except item 8.1, 13.4, 24.1 - but none of them related to material group). So we can consider this material has P No.1 and P Group No.1 w/o S No. and S Group No.
- As per ASME IX 2007 edition, QW 420.2, para. 3, we can not using Base Metal have S No. and S Group No. for qualification and apply to Base Metal only have P No. and P Group No. w/o S No. and S Group No.
- So, their welding procedure is not suitable for our project.

After that, they were so angry, because they welded hundreds of joints. They send letter, said that their WPS using Base Metal with two options (see previous):
+ P No.: S No.1; P Group No.: S Group No.1; OR
+ API 5L Gr.B or equivalent;
and because of API 5L Gr.B is equivalent with ASTM A-106 Gr.B so their welding procesure is suitable for this project.

I informed again with them that: "equivalent" in their sentence mean that any material have S No.1 and S Group No.1.

Please help me to clarify that:
- Is my explanation is correct?
- Can we using their welding procedure to our project?
- do you have any suggestion to solve this problem?

With Kind Regards.


Johawn

 

[metengr]

Johawn;
You are not correct. ASME Section IX recognizes that S-No base material can only be used for qualification with other S-No base materials for a WPS. For example ASTM A 106 is assigned as an S-No 1, while SA 106 would be assigned a P-No 1. If your project had SA 106 material or this material was dual certified as A/SA 106, your position would be correct.

The provisions of QW-402.3 are very clear that material with SA designation are assigned P-No's and those that are A or under a UNS designation are assigned S-No.

 

[metengr]

The provisions of QW-402.3...

This is a typo, it should stated QW-420.2

 

[Johawn]

Hi metengr,

Thank you for your prompt reply !

Please let me clarify what am I understanding as per your explanation:

- As per ASME IX edition 2007, QW-420.2, para. 2: ASME SA-106 Gr.B have P No.1 and P Group No.1 so ASTM A-106 Gr.B would have P No.1 and P Group No.1 & S No.1 and S Group No.1

- Welding procedure using using API 5L Gr.B as Base Metal have S No.1 and S Group No.1 can apply for material ASTM A-106 Gr.B.

(please note that our material only ASTM A-106 Gr.B)

Rgds.

Johawn

 

[metengr]

Johawn;

so ASTM A-106 Gr.B would have P No.1 and P Group No.1 & S No.1 and S Group No.1

No, ASTM A 106 has only an S-No 1 Group 1 assignment, and does not have a P-No assignment per paragraph 2 in QW-420.2. Look in Table QW-422, for ASME SA 106 this material is assigned a P-No 1. ASTM A 106 is not listed in QW-422, therefore this is assigned an S-No 1 Group No 1.

If the PQR would have been qualified using SA 106 Grade B this would allow for P-No and S-No interchangeability in a WPS.

Your vendor is absolutely correct for being able to use this WPS for welding ASTM A 106 material.

 

[Johawn]

Hi metengr,

Noted with many thanks.

I inform to our client that their WPS can apply to our project.

Best Regards.


Johawn.