 # What is Hoop Stress in pressure vessel?

Stress in Cylindrical Component 1;

Pressure or pressure within a component that is cylindrical (Cylinder) will cause stress or stress on the component, both the longitudinal stress ( Circumferential stress). Stress in Cylindrical Component 2;

Considering the cylindrical Vessel and Pipe, which have the Longitudinal Weld and the Circumferential Weld, we see that the Longitudinal stress is dealt with the Circ. Weld and stresses along the circumference ( circumferential stress) are done with the Long. the Weld. Stress in Cylindrical Component 3;

Normally, the circumferential stress is twice that of the longitudinal stress observed in daily life. We will see that the sausage will always break along the long lines. Same as thin tubes Or cans of color that have been heated also break along the same length.

Therefore, for the Vessel and Pipe, which are cylindrical components, the longitudinal weld ( Long. Weld) is more important than the welding of the circumference ( Circ. Weld). Circumferential vs Longitudinal Stress of a Cylindrical Shell in ASME VIII Vessels;

Let’s look at the formula for calculating the Cylindrical Shell thickness of the ASME Section VIII Pressure Vessel. We can see that the Minimum Thickness calculated from Circumferential Stress is approximately twice the thickness calculated from Longitudinal Stress. This is because the Circumferential Stress is twice as much as Longitudinal Stress. Therefore, when calculating Shell thickness, use the formula of Circumferential Stress. 