PWHT Soaking time for Overlayed T/S 1

[bmoorthy]

Hello all

I have a low alloy steel Tube sheet. This needs to be Overlayed with E 309MoL followed by E 316L. There is no other welding involved as the exchanger is AES type and the tube to tube sheet joint is expanded type.

The client specification calls for PWHT after all the welding is complete.

The thickness of the tube sheet is 100mm.

What should be the soaking time?

The design is ASME Sec VIII Div 1.

 

[metengr]

The soaking time is based on the thickness of the weld deposit, not the base metal thickness.

 

[SJones]

And then perform an ASTM A262 test to see that you have not sensitised the stainless steel! Ideally, this testing should be part of the WPQR.

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdo/

 

[bmoorthy]

Thank you both of you.

Metenger

Yes i agree with your recommendation it is common sense.

Is there a specific clause in ASME or any other code/Standard/Specification which specifies that the thickness to be considered is the thickness of the weld deposit overlay (UW 40 does not deal with such issues).

Regards

B.Moorthy

 

[ijzer]

See UCL-34 for thickness definition in case of weld overlay

 

[jte]

B. Moorthy-

See Interpretation VIII-1-83-192 (Int Vol. 14 page 108).

..., and the minimum holding time is based on the weld overlay thickness.

jt

 

[Eabrar]

HI BMOORTHY AND EVERYONE

IS THERE ANY CLASSIFICATION AVAILABLE (EXCEPT EXPERIENCE) FOR THE JOINT TYPE OF TUBE-TUBESHEET (LIKE SEAL,STRENGTH,EXPANDED ETC) WITH REFERNCE TO DESIGN CONDITIONS/SERIVE/EXCHANGER TYPE ETC?

THANKING U PPL IN ADVANCE

 

[weldtek]

Keep in mind the interpretation jte refers to is dealing with P 5 mat'l

 

[bmoorthy]

Eabrar

Refer to ASME Sec VIII Div 1 Appendix A and AA for joint classification. Also you may want to check TEMA (Recommended Practices).