sa-283-c material

[Tweetybird]

I am working with some older pressure vessels circa 1960. the shell material is stated as sa-283-c "tq"; the head material is sa-283-c "fq"; I have worked with sa-283-c many times but am unfamilur with "tq" "fq"
Any help?

 

[JStephen]

Forging quality? Firebox quality? Forming quality?

 

[Christine74]

I suspect it's SA-285-C, not SA-283-C because SA-283-C is a structural steel spec.

I haven't seen TQ or FQ but SA-285-C is sometimes followed by "FBX", indicating Firebox steel.

-Christine

 

[TGS4]

It's likely firebox quality. SA-283 C is permitted in pressure vessels, with some caveats. My guess is that the "tq" is just a typo/misprint/repro problem.