SA-312 TP316 Creep Temperature

[OnG_Engr]

All,

I have an application where the design temperature is between 1100F and 1150F. In Section II, Part D, there are two rows dedicated to SA-312 TP316 "smls. & wld. pipe" (#32 an d#33) The first row has a creep temperature that begins at 1100F (note T8) and the row below begins at 1150F (note T9).
(1) What's the difference between these two?
(2) How do differentiate between these two when ordering?

I know #33 has a lower allowable stress, but I need more info than that.

Appreciate replies.

 

[EdStainless]

I don't recall the notes, but I will make another comment.
Make sure that your material is not 316L.
Just because the RT strength is high enough for 316 the lower C will lower the creep properties.
Often 316L is plenty strong because of residual N, this does not help creep resistance.

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P.E. Metallurgy, consulting work welcomed

 

[SnTMan]

OnG_Engr, check for note G5. Likely one line is for higher allowables, one for lower.

Plus, what Ed said

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[XL83NL]

At these temperatures, you require per on Eid the G-notes the higher carbon content. This practically means you need 316H. There may be a code case for 316 @1000+ F, but don’t get your hopes up too high.

Huub
- You never get what you expect, you only get what you inspect.

 

[OnG_Engr]

Appreciation for the responses! I agree that one needs to be careful about not going with 316L due to the carbon content. I also looked up 316H but didn't see any advantage. I tried Section II, Part A but didn't see anything there. The only pattern I could see was that the row with the lower allowable pressure kept out of the creep range. Does this mean that if I use a lower allowable I can go with slightly higher temps, or is there some else I have to do?

I definitely need to fill that hole in my Section II knowledge.

Again, thank you for responding.

 

[XL83NL]

Lower allowable stress you mean ;-).

It doesn’t keep out of creep, the allowable isn’t governed by creep. That’s a difference.

Also, you’re missing the carbon content note (G-something) that will basically kick you to 316H at 1000F+.

Huub
- You never get what you expect, you only get what you inspect.

 

[EdStainless]

And there is a note somewhere (maybe in the material spec) about the required HT.

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P.E. Metallurgy, consulting work welcomed