[Steam-engine] Maximum Allowable Pressure for Vertical Unstayed Firebox

[Lawrence Swanz]

Members,

I am looking for a formula from the 1971 code book that deals with firebox's in vertical boilers.  I was always under the understanding that the barrel formula was used, since it is nothing more than a smaller barrel inside of a barrel, but that isn't the case, because the barrel formula is used to figure outward stress and not inward or crushing stress, which would be the case on a vertical boiler.  Does anyone know what this formula is or have access to the 1971 code that would address this?  Thanks.

Lawrence J. Swanz