Pressure Vessel Wall Thickness Calculator
Find the minimum shell wall thickness for a thin-wall cylindrical pressure vessel from internal pressure, diameter, allowable stress, and joint efficiency.
Enter your values
Design pressure, geometry, and material allowable stress.
How this calculator works
For a thin-wall cylindrical shell (wall thickness less than about 1/10 of the internal radius), the governing case is circumferential (hoop) stress, giving minimum required thickness:
P is internal design pressure, D is internal diameter, S is the material's allowable stress at design temperature, and E is the weld joint efficiency. A corrosion allowance, if specified, is added on top of this calculated minimum:
Typical joint efficiency values
| Weld examination | Typical E |
|---|---|
| Full radiography | 1.00 |
| Spot radiography | 0.85 |
| No radiography | 0.70 |
This is a simplified thin-wall check, not a substitute for a full code calculation (e.g. ASME Section VIII) which also covers heads, nozzles, and thick-wall cases.
Frequently asked questions
Does this apply to spherical vessels?
No — spherical shells use t = PD/(4SE), half the cylindrical hoop-stress formula, since a sphere carries stress equally in both directions. This calculator covers cylindrical shells only.
Is this suitable for final vessel design?
Use it for early sizing and estimation. A certified vessel design must follow the applicable pressure vessel code in full, including head, nozzle, and fatigue checks, and should be reviewed by a qualified pressure vessel engineer.