Dear All,

Pls refer to the roof specification parameters menu of the Coade Tank - General Roof Specs - Net Area at Roof/Shell Junction (A)

Coade Tank software send us to Appendix F and the related formula is as below (acc. to API 650 2009 Appendix F.5.1)

A = 220(D^2)x(Pi-0.08 ti)/(Fy x Tan0)

D : Diamater
Pi : Internal Design Pressure

My question is that if the internal design pressure is zero (athmospheric tank) then Junction Area (A) will be minus value. Is there any calculation method for the Junction Area (A) ?

Thanks for the help