API 650 Annex F.4.2 - Maximum design pressure limited by uplift
API 650 Annex F.4.2 - Maximum design pressure limited by uplift
(OP)
Hi, I have a question about calculating the maximum design pressure for unanchored tanks limited by uplift at the base of the shell. in API 650 Annex F.4.2 the equation is given by:
Pmax = (0.000849*DLs/D2) + (0.00127*DLR/D2) - (0.00153*Mw/D3)
My problem is that I'm not able to figure out how to calculate Mw (the wind moment in Nm). I have tried to find the answer in API 650, but I don't understand their descriptions. Can anyone help me? The wind moment is the only value I'm missing in my calculations.
Best regards, Soren
Pmax = (0.000849*DLs/D2) + (0.00127*DLR/D2) - (0.00153*Mw/D3)
My problem is that I'm not able to figure out how to calculate Mw (the wind moment in Nm). I have tried to find the answer in API 650, but I don't understand their descriptions. Can anyone help me? The wind moment is the only value I'm missing in my calculations.
Best regards, Soren





RE: API 650 Annex F.4.2 - Maximum design pressure limited by uplift
RE: API 650 Annex F.4.2 - Maximum design pressure limited by uplift
Yes I have found the wind pressure and velocity in 5.2.1.k. But isn't there a formula for the wind moment? I can't seem to find the Free Body Diagram that you mention?
Figure 5.27 (page 5-94) only shows the Overturning Check for Uanchored Tanks. I am not sure I understand what you mean.
RE: API 650 Annex F.4.2 - Maximum design pressure limited by uplift
Wind horizontal force = Wind pressure multiplied by vertical projected area
Wind horizontal moment arm = Half of the tank height
Wind vertical force (uplift) = Uplift pressure multiplied by horizontal projected area
Wind vertical moment arm = Half of the tank diameter
Mw = (Pws)(D)(H)(H/2)+(Pwr)(pi*D^2/4)(D/2)
RE: API 650 Annex F.4.2 - Maximum design pressure limited by uplift
RE: API 650 Annex F.4.2 - Maximum design pressure limited by uplift
I have a question about calculating the maximum design pressure for unanchored tankse a question on Annex F. The roof tank is supported by column.
In F.4.1 Dlr equals to the amount of the nominal weight of roof plate and rafters supported by the roof-to-shell junction. The other one being supported by columns.
Am i right?
And i also have to check roof-to-shell junction with forces from roof struture.
Best regards