Heat exchanger design for 500 degC - fittings

[Happydays123]

Hi,
Got an application that currently uses ASTM A403 WP304L fittings and I'm looking at using WP316L. The fittings are part of a heat exchanger and will be exposed to temperatures approx. 500 degC. Are there any concerns regarding the change in material, such as hardness and longevity?

Cheers
Digs

 

[metengr]

Is this heat exchanger ASME code stamped? The reason I ask is that the A 403 material is not used for ASME pressure fittings.

 

[Happydays123]

No exchanger is stamper AS1228

 

[metengr]

Check with the Australian construction code for advice on acceptable materials.

 

[D2HANDLE]

Hello metengr - I am a little surprised with your statement

[ The reason I ask is that the A 403 material is not used for ASME pressure fittings./quote]

SA 403 fittings are very common to be used in ASME Vessels and Heat exchanges.
Why would say that they are not allowed?

Kindly clarify your position.

Thanks,
D2HANDLE

 

[metengr]

Can you show me where A 403 material specification is specifically referenced within a material group in ASME B16.5 or 34?

 

[D2HANDLE]

metengr,

I was talking about the wrought butt welded fittings such as Elbows, tees, Reducers etc. in accordance with ASME B16.9.

D2HANDLE

 

[metengr]

I believe if you review this standard the list of material groupings refers back to material groupings in B16.34.

 

[D2HANDLE]

I am confused again......
B16.34 is the standard for Valves — Flanged, Threaded, and Welding End.
Are you sure you are referrring to this B 16.34?

Also, the materials allowed for wrought fittings are all mentioned in Par. 5 of the standard, and I cannot find any reference to B 16.34 for the material grouping.

 

[metengr]

D2HANDLE
I was able to retrieve my copy of ASME B16.9, and A 403 is indeed listed. My apologies. I was thinking of B16.5.

 

[XL83NL]

If it's the 'real' L-grade of 316 youre dealing with (and not the straight or the dual certified one), then 500°C may be a concern.

ASME II-D, although probably not applicable to your situation, lists L-grade up to a max of 454°C. Same counts for B16.5 (but then for 304L forgings).
It's in there for a reason, even if youre not working to any ASME standard, consider those reasons.

 

[Happydays123]

Thanks guys, much appreciated.