Deflection of Diesel storage tank of thickness 4.0 mm sheet

[salman20]

My old Diesel Storage tank designing is OD=1.5 meter, Length=3.672 Meter Thickness is 6.0 mm capacity 6450 L according to API 650. No. of saddles=3

New designing is OD=1.6 meter, Length=3.66 meter, thickness=4.0mm, capacity 7000L No. of saddles is 3
Both material is Mild steel A36 code=|Australian code of storage tank(petroleum etc.) tank dish ends are flat in both cases.

I want to know only in new design that what about danger of leakage. can it fail due to heavy load of diesel 6000 kg and its own load=2000 kg.
Please help me beacause i want to know about sheets of 4.0 mm deflection downside. I am in tension because API 650 does not recommend thickness below 5.0 mm in any case. But Australian code allows 3.0 mm sheet. in all over the world API codes are to be reffered. New designing does not belong to me. old work is my own designing.please help me.

[marian_g]

How to correlate two calculation concepts- one for a thin vessel on 3 saddles and other for an API 650 tank which must have a continuous foundation under bottom?

[Arrayxxx]

are the bottom of tank is supported by cap foundation or elevated above ground?
if the bottom is lay on the floor, then you don't have any problem
if the bottom is elevated and supported by structure/skirt, then you must add some stiffener in the bottom side, just simulate using FEA then you will know stress level in the bottom.

[Arrayxxx]

are the bottom of tank is supported by cap foundation or elevated above ground?
if the bottom is lay on the floor, then you don't have any problem
if the bottom is elevated and supported by structure/skirt, then you must add some stiffener in the bottom side, just simulate using FEA then you will know stress level in the bottom.

[additional]

are those saddles for anchor ? I don't get it whether this is a vertical or horizontal tank ?