B31.1 Power Piping: Question of using ASTM A106 Grade B

[SteamEjectors]

Dear all,

reg. ASME B31.1 Power Piping the use at temperatures above maximum in stress tables given is generally not permitted.
That means in fact you can use ASTM A106 Grade B until 800 °F (426°C) for Power Piping and not above...
Are there any exceptions? For example low pressure?

In our special case we have Design Conditions from
p= 0,5 barg (7.25 psig) T=435°C (815°F)in a
Vacuum Application.
We don´t really want to use high alloy- material (F11).

Are there alternatives or any exceptions for using ASTM A106 Grade B for higher temperatures?

Thanks for every helpful answer.

 

[ione]

Regards

http://www.engineeringtoolbox.com/astm-steel-pipes-pressure-temperature-d_742.html

 

[SteamEjectors]

Dear Ione,

thanks for your quick answer. But the problem is that this
table is for B31.3 Process Piping and not for B31.1 Power Piping . It is right that for B31.3 the stress value or ,in fact, the allowable Temperatures are higher for Material SA 106 Gr. B.
But the customer wants B31.1 also for the vacuum lines.
So, I´m searching for a way out of this problem inside of B31.1 and not to change from B31.1 to B31.3.
The customer specification requires B31.1... :-(

Nevertheless, thanks a lot for your answer.

Best regards

 

[ione]

Oh sorry, my miss.

Well it seems you do not have many options available.
Please take a look at the thread below, you could find it useful

http://www.eng-tips.com/viewthread.cfm?qid=141153&page=69

 

[SteamEjectors]

Thanks for your reply & for the thread. It really seems that we have to use low alloy steel.