I'm looking at a customer drawing of a vessel built in 1966. Most materials referenced are 285 C but some are listed as A7. I suspect this A7 was a carbon steel structural spec probably roughly comparable to todays A36. Can anyone offer any insight?
SA-7 Steel for Bridges and Buildings.
It could be used for unfired pressure vessels if:
Not in lethal service
Not in unfired steam boilers.
Used in temperatures -20°F to 650°F
No strength weld over 5/9"
Manufactured by the process permitted by the Specification.
Min Tensile 60,000 Allowable -20°F to 650°F 12.650