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Pressure Vessel Calculator

Thin/thick wall hoop and longitudinal stress in cylindrical pressure vessels.

Calculate hoop and longitudinal stresses in cylindrical or spherical pressure vessels, and required wall thickness.

Reference: ASME Boiler & Pressure Vessel Code (thin-wall theory) / Lamé's Equations

Pressure Vessel Calculator (Thin & Thick Wall)

Inputs

Results

Thin-wall Assumption Valid?
Yes (t/r < 0.1)
t/r Ratio
0.040
Hoop (Circumferential) Stress
50.0MPa
Longitudinal Stress
25.0MPa
Thick-wall Hoop Stress (Lamé, inner surface)
51.0MPa
Required Thickness (thin-wall, at allowable)
3.57mm
Factor of Safety
2.80

Formula Used

Cyl: σh=Pd/2t, σl=Pd/4t  |  Sphere: σ=Pd/4t  |  Lamé: σh,max=P(ro²+ri²)/(ro²-ri²)
Thin-wall theory is accurate when wall thickness is less than ~10% of inner radius. Beyond that, stress varies through the wall thickness — use the Lamé thick-wall result instead for design.

⚠ For preliminary design and educational use only. Verify all results against applicable codes and standards before use in production or safety-critical applications.

About this calculator

Part of our Mechanical Calculators collection. Beams, bolts, springs, gears, bearings, and core ME calculations.

How it works

Calculates hoop, longitudinal, and radial stresses in thin-wall (membrane theory) and thick-wall (Lamé equations) cylindrical pressure vessels.

Enter your values in the inputs above and click CALCULATE. Results appear on the right without a page reload. No login and no server upload.

Privacy and accuracy

Every calculation runs locally in your browser. Your design data never leaves your device. Results are intended for preliminary engineering work. Always verify critical designs with qualified review and applicable standards before production use.

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