SA-455 Material

[FoxRox]

Trying to redesign an old vessel to latest code version. The old design had SA-455 shells and heads. Is this material no longer common or readily available for some reason? ASME BPVC Section VIII Div 1 Table UCS-23 allows the material, but our purchasing team is getting no-bids from all our usual mills and component manufacturers. Anyone have an explanation?

 

I took a look at SA-455, which I have no prior experience with.
If thickness is 0.58" or greater then SA-516-70 will meet or exceed the tensile properties and thus be a direct substitute (and it is very available).
For lower thickness where the UTS of SA-455 is greater than that of SA-516-70, you should try to justify its selection through the design calcs. I suspect your chances are good.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[FoxRox]

Thanks for the reply. We are under 3/8", and in this case the marginal difference in allowable stress does make a difference on the nominal thickness we will need to use. However, I agree that SA-516 70 will almost undoubtedly win an economic comparison, especially if we don't manage to find a vendor for SA-455. That makes the choice pretty simple.

 

[Don56]

I have used a lot of SA-455 making heads as well as SA-414G which is a similar sheet spec. I doubt you will find SA-455 at a steel warehouse. Most likely a mill buy.

 

FoxRox,

At that thickness, thickening the PV by 1/16" in a few components will likely have negligible cost impact.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[SnTMan]

Probably. Don't spend a lot of time looking for 7/16" plate though....

Regards,

Mike

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

 

[RayHam475]

In my experience, I have only seen SA-414G and SA-455 used in air receivers. The small ones are SA-414G, then as the vessels get bigger they use SA-455, then after a certain size SA-516-70 is used.