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Up Topic Welding Industry / Technical Discussions / Heat Treatment of tube bends
- - By aliffc3 (*) Date 05-23-2004 17:58
We have a fabrication case of a boiler feed water heat exchanger. The tubes are SA-209 T1. This is a U-tube exchanger. The question is what code governs the requirement of Heat treatment of the tubes after making U-bends?

Thanks in advance.
Parent - - By Niekie3 (***) Date 05-24-2004 13:52
Hi

The design and fabrication code according to which the exchanger is designed will give you this information. In general, you need to make a calculation regarding the amount of "fibre elongation". If it exceeds a critical amount, heat treatment is required. Sometimes you will need to heat treat due to service requirements. (e.g. Prone to stress corrosion cracking.)

Hope this helps.

Regards
Niekie Jooste
Fabristruct Solutions
Parent - - By aliffc3 (*) Date 05-24-2004 17:00
The exhanger is designed on TEMA-R and ASME SEC VIII Div.1. Still not able to locate the desired information.
Parent - By Niekie3 (***) Date 05-24-2004 19:15
Hi

TEMA Section 5 RCB-2.31 gives ways of calculating wall thinning. RCB-2.33 states that under certain circumstances heat treatment may be required when agreed between manufacturer and purchaser.

Often, end-users require heat treatment when fibre elongation values exceed those given in ASME VIII Div 1 - UCS-79(d), or the maximum wall thinning requirements have been exceeded. Also, if the exchanger will be in a stress corrosion cracking service.

I could not get anything more direct than this. Hope it helps.

Regards
Niekie Jooste
Fabristruct Solutions


Parent - - By G.S.Crisi (****) Date 05-24-2004 17:07
Very simple. The Code that governs tubes made to ASME SA-209 Gr T1 is the ASME Boiler and Pressure Vessel Code, Section II: "Material Specifications".
Grab Section II of the ASME Boiler Code, go to SA-209, once in there search for Grade T1 and it'll say whether or not the tubes must be stress relieved after bending.
In the majority of times, ASME material specs. are identical with ASTM ones of the same number (in this case A-209), but sometimes are not, so I don't recommend you to go to ASTM.
What TEMA governs is the mechanical design of the heat exchanger as a whole, while ASME Code Section VIII Div. 1 governs the design and construction of the shell and headers.
The tubes, on the other hand, are under SA-209, as explained above.
Giovanni S. Crisi
Sao Paulo - Brazil
Parent - - By aliffc3 (*) Date 05-24-2004 17:38
Grabbed ASME sec II, went to SA-209 T1 but no info on that in the related notes. Just to be sure also checked SA-213 T22 which I think for sure requires HT after bending but no such information found......
Parent - - By MBSims (****) Date 05-26-2004 03:07
If a code requirement exists to perform heat treatment after bending or forming, it will be in ASME VIII. I don't have one here at home, but will look tomorrow at work. I don't recall this material requiring post-bending HT, but I may be wrong.
Parent - By aliffc3 (*) Date 05-27-2004 17:55
I am waiting for your responce.

Thanks.
Up Topic Welding Industry / Technical Discussions / Heat Treatment of tube bends

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