PRESSURE VESSEL DESIGN

PRESSURE VESSEL DESIGN

Oleh : Bayu Nurwinanto

Pressure Vessel Design Models For Cylinders

• Thick-walled Cylinders

Thick Wall Theory :

Thick-wall theory is developed from the Theory of Elasticity which yields the state of stress as a continuous function of radius over the pressure vessel wall. The state of stress is defined relative to a convenient cylindrical coordinate system:

1. σ t — Tangential Stress
2. σ r — Radial Stress
3. σ l — Longitudinal Stress

Stresses in a cylindrical pressure vessel depend upon the ratio of the inner radius to the outer radius ( ro / ri ) rather than the size of the cylinder.

Principal Stresses (s ₁, s ₂ , s₃)

1. Determined without computation of Mohr’s Circle
2. Equivalent to cylindrical stresses (σ t ,σ r ,s₁)

Cylinder under Pressure :
Consider a cylinder, with capped ends, subjected to an internal pressure, pi, and an external pressure, po,