What is an Ellipsoidal Head Tank?
An ellipsoidal head tank features dished ends shaped with a 2:1 elliptical cross-section. This standardized geometric shape offers optimum wall strength and volume for high-pressure boilers and chemical reactors.
Reference codes at ASME Boiler & Pressure Vessel Code.
How This Calculator Works
To use this calculator, enter the inside diameter (D) of your ellipsoidal head and optional straight flange height (sf). The calculator converts all dimensions to meters, applies the 2:1 semi-ellipsoidal volume equation, and outputs total liquid capacity in US Gallons, Litres, Cubic Feet, Cubic Meters, and Imperial Gallons. For complete tank calculations, see our dish-end tank volume calculator and fuel tank volume calculator.
How to Use the Ellipsoidal Head Volume Calculator
Easily determine 2:1 semi-ellipsoidal head capacity with these clear point-by-point steps:
- Enter Head Inside Diameter (D): Measure and input the internal diameter of the pressure vessel head.
- Enter Straight Flange Height (sf): Input the straight flange length (leave blank if zero).
- Choose Measurement Units: Select ft, in, m, or cm for accurate dimension conversion.
- Click "Calculate Volume": Submit the form to compute the 2:1 semi-ellipsoidal dome volume.
- Check Results Table: View total liquid capacity displayed in US Gallons, Litres, Cubic Feet, Cubic Meters, and UK Gallons.
ASME 2:1 Semi-Ellipsoidal Head Volume Formula
For a standard ASME 2:1 semi-ellipsoidal head, the minor axis depth equals one-fourth of the inside diameter (h = D / 4). The internal volume formula combines the semi-ellipsoid dome volume and straight flange cylinder volume:
2:1 Ellipsoidal Head Formula:
Volume = (π / 24) × D³ + (π / 4) × D² × sf
Where D is inside diameter and sf is straight flange length.
Advantages of 2:1 Ellipsoidal Dished Heads
Ellipsoidal heads provide smooth stress transitions under high internal pressures, reducing required wall thickness compared to flat or shallow dished ends while maintaining high liquid capacity. Scientific geometry reference: Wolfram MathWorld Ellipsoidal Geometry Reference.
Standard Tank Capacity & Volume Sizing Chart
| Tank Sizing / Model | Typical Dimensions | Litres | US Gallons |
|---|---|---|---|
| 500 Litres (132 gal) | 0.86m × 0.95m (2.8ft × 3.1ft) | 500 L | 132 gal |
| 1,000 Litres (264 gal) | 1.10m × 1.15m (3.6ft × 3.8ft) | 1,000 L | 264 gal |
| 2,500 Litres (660 gal) | 1.45m × 1.60m (4.8ft × 5.2ft) | 2,500 L | 660 gal |
| 5,000 Litres (1,320 gal) | 1.85m × 1.95m (6.1ft × 6.4ft) | 5,000 L | 1,320 gal |
| 10,000 Litres (2,640 gal) | 2.35m × 2.40m (7.7ft × 7.9ft) | 10,000 L | 2,640 gal |