Firebox quality steel

[Biss73]

Hi,
I'm working on an 1948 heat exchanger which has a shell in SA-201 Gr B FBQ.

Does an FBQ grade steel respects by default ASTM A300?

If yes, is the -50F minimum temperature requirement (seen in some threads) valid for all steel under A300?

If no, does anyone know what is the minimum temperature requirement when a steel is FBQ?

Thanks,
Biss

 

[metengr]

Does an FBQ grade steel respects by default ASTM A300?

No. I reviewed my copy of ASME SA 300-52 and flange or firebox quality steel could be specified to meet SA 300. It depends on how the steel was supplied - fine grained. Coarse grain could also have been supplied.

Does an FBQ grade steel respects by default ASTM A300?

No.

 

[stanweld]

FBX "Fire Box" quality simply means fully Silicon deoxidized "killed" steel.

 

[Biss73]

So having a firebox quality steel does not necessarely translate into a lower mdmt?

Thanks,
Biss

 

[metengr]

Correct.

 

[Biss73]

SA-201 Gr B FBQ was replaced by SA-515 Gr 60 in 1967. Does someone know if they have the same Fig UCS-66 B curve?

Thanks again,
Biss