Flange Temperature Ratings

[DDario]

Hi all,

I am designing a system using 3" 150# WN Flanges, 316SS

One of my suppliers gave me a low temperature rating of -20F,

My project will be going into an arctic environment, with temperatures reaching -50F or lower,

I hadn't thought for a second that a 316 flange would have a problem, but now I am second guessing myself.

Any idea what this rating would apply to, or in reference of? Any experience here in arctic environments on this issue?

Thanks

 

[rneill]

If you look at the MDMT for A182 F316 material in ASME B31.3, it is much much lower than -20F. Not sure why the supplier is quoting -20F ... why don't you point out the discrepancy with B31.3 and ask him to explain.

 

[JLSeagull]

In ASME B16.5 and B16.34 type 316 is material group 2.2 and 316L is group 2.3. Both F2 series tables start at -20 degree F (29 C) and go up from there. Perhaps the ASME flange and valve tables could use some work on the cold end.

 

[rneill]

True, I always just ignore the minimum temperature shown in B16.5 and B16.34. At a minimum, there should probably be a note explaining that the MDMT would be as per the applicable design code and that the rating applies from the MDMT and up.

 

[Canadieng]

rneill;

The B16.5 paragraphs 2.4, 2.5.3, & 5.1.2 cover exactly that.