ASME IX / QW-217 (b)

[Isac Passaura]

l like to get opinions on the interpretation of ASME Section IX, QW-217 Method  B

Joint type: butt weld on a Composite tube 

• The cladding thickness is NOT included in the design calculations

Proposed welding sequence:

• A + B: weld thebase metal portion using GTAW + ER70S-3
• C: restore the corrosion-resistant cladding using SMAW + E309L

So, in practical terms:

• A+B = the base metal portion of the weldment
• C = the corrosion-resistant overlay portion of the weld 

My question

Under QW-217(b)(1), the Code says:

“The essential and nonessential variables of QW-250 shall apply for each welding process used in production for joining the base metal portion of the weldment. The PQRs that support this portion of the WPS need not be based on test coupons made with clad metal. For the corrosion-resistant overlay portion of the weld, the essential variables of QW-251.4 shall apply and the test coupon and testing shall be in accordance with Table QW-453. The WPS shall limit the depth of the groove, which will receive the corrosion-resistant overlay in order to ensure development of the full strength of the underlying weld in the base metal.”

My current interpretation is:

1. The explicit relief regarding non-clad test coupons applies only to the base metal portion of the weldment.
2. Therefore, the A+B groove weld PQR may be qualified on a non-clad coupon.
3. However, that same sentence does not automatically extend to the corrosion-resistant overlay portion.
4. For C, the qualification must follow the specific overlay route referenced in QW-251.4 / Table QW-453.
5. The wording “this portion of the WPS” seems intentionally limited to the base-metal-joining portion, not the entire WPS.

Main doubt

Would you agree that:

• a single production WPS may be supported by:
  • one groove weld PQR on non-clad material for the load-carrying portion, and
  • one overlay PQR on non-clad material for the corrosion-resistant restoration portion, according to QW-214
• or

• • one groove weld PQR on non-clad material for the load-carrying portion, and
  • one overlay PQR in clad material with a section of clad removed  for the corrosion-resistant restoration portion 
  • 
    

 Thanks.