Strap vertical tanks with pi/4 D^2 h, horizontal tanks with the fill-factor table, add 2:1 SE heads, and time transfers with t = V/Q.
Vertical tanks and heads
Volume is cross-section times level: DN2000 x 5 m holds 15.71 m3 in the shell. Each 2:1 SE head adds 1.048 m3, so the closed vessel holds 17.81 m3 before freeboard.
Horizontal tanks need the table
Level fraction maps nonlinearly to volume through the circular-segment factor; the 6 m x DN2000 example holds 9.42 m3 at half full. Build the operator table in 5-10 cm steps rather than interpolating by eye.
Tables operators actually use
Tabulate level to volume including heads, mark alarm and interlock levels directly in volume, and attach the fill-time estimate so transfers are planned, not watched.
Formulas
Vertical shell
V = (pi/4)D^2 h
Add heads separately.
SE head
V_head = 0.131 D^3
Per 2:1 semi-elliptical head.
Fill time
t = V/Q
Constant-rate transfers.
Worked example
DN2000 vertical x 5 m
Inputs: D 2; h 5.
Calculation: Shell 15.71 m3; plus two heads 2.10 m3.
Frequently asked questions
Vertical tank formula?
Area times level; add heads separately.
Why is half level not half volume in horizontal tanks?
Level fraction is nonlinear; use the strapping table or segment formula.
How much do dished heads add?
About 0.131 D^3 per 2:1 SE head.
Sources and further verification
- Storage tank — Wikipedia
- Pressure vessel — Wikipedia
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