This refers to Design Pressure (P) calculations for anchored tanks as per Annex F.4.1.Though the individual components for the calculation of P are correctly worked out, on substitution in the equation the result arrived at seems erroneous. A typical case is extracted below. The final value 43.209 shown seems much lower than actual.

Design Pressure per F.4.1 [P]:
= (0.962 * A * Fy * tan(theta))/(D^2) + 0.245 * DLR/D^2
= (0.962*8.679*19166.4*tan(14.00))/(29.5^2)+0.245*28920/29.5^2
= 43.209 in. of water [1097.508 mm. of water]
= 1.560 psi [0.011 N./]

Request clarification if other conditions prevail on above.