Thin Walled Pressure Vessels

A thin walled pressure vessel is generally considered to be one whose walls are less than about 1/10 or 1/20 of the radius of the vessel. The formulas provided below are for reference and calculation, but before constructing a real pressure vessel you should check with an engineer. The information is provided for your reference. Remember that a catastrophic failure of a vessel could result in serious injury or death.

Longitudinal Stress

\(\sigma_l = \frac{p d}{4 t}\)

Circumferential (Hoop) Stress

\(\sigma_h = \frac{p d}{2 t}\)

Nomenclature

• \(\sigma_h\) = Hoop Stress
• \(\sigma_l\) = Longitudinal Stress
• \(p\) = Internal pressure
• \(d\) = Internal diameter of the tube
• \(t\) = Wall thickness