U bend tube stress relieve

[roniprabowo]

Dear all,
Could you please give me an advice. I have u tube of A 213 T11 (1.25 Cr - 0.5 Mo). Do I need stress relieve for these tubes ? Is there any code regarding this matter ?

Thanks a lot.

 

[metengr]

No, there is no specific code requirement that I am aware of. However, it would be a good idea to stress relieve the U-bends. Per SA 213,the tubes would be furnished in the annealed or normalized and tempered condition for grade T11. After the U-bending operation, the stress relief should be performed 50 deg F below the original specified minimum tempering temperature of 1200 deg F for T11 material.

 

[rmw]

What is the application?? There may be a code governing the specific application like SA-688 XXX for HP feedwater heater tubing. That metallurgy tube for that application would certainly have to be stress relieved in the U bends.

rmw

 

[metengr]

rmw;
I believe there is no requirement for stress relief of U bends furnished under SA 213 T11 material specification used in Section I or Section VIII applications. SA 688 applies only to austenitic stainless steel tubes for feedwater heaters.

 

[rmw]

metengr,

You are the person I wanted to hear that from. Steel alloy tubing is just beginning to be used again in T11 and T22 grades, and I was unsure if like SA-688 TPXXX there was such a requriement for the steel tubing. My inside expert is in the process of relocating offices, and unavailable to me for a few days. Thanks for pinch hitting. I value your contributions to this forum.

rmw