1964 ASME Form U-1

[numberfive]

I have a data report (ASME Form U-1) for a pressure vessel built in 1964.

Line 4. "SHELL" is completed as follows: Material - A285, Gr. C /
T.S. - F.B. 55,000 / Nominal Thickness - 1/2 in. / Corrosion Allowance - None / Diam. - 9ft. 4in. / Length - 28ft. 0in.

In parenthesis under the space for tensile strength (T.S.) the form reads (Fig. or F.B. & Spec. Min. T.S.)

Can anyone tell me what F.B. stands for? I've seen this on other data reports for older pressure vessels but do not know what it means.

Any insight would be greatly appreciated.

 

[doct9960]

In parenthesis under the space for tensile strength (T.S.) the form reads (Fig. or F.B. & Spec. Min. T.S.)

Fig. is a typo. It should be Flg.
Flg. = Flange Quality Steel
F.B. = Firebox Quality Steel

Also have a look at thread794-170041