The tank is filled with a fluid that has an internal gage pressure of p = 1,500 kPa. The fluid pressure creates stresses in the tank wall.
The fluid pressure also creates a normal stress that acts around the circumference of the tank. The hoop stress is related to the tank pressure p by:
where r = inside radius, d = inside diameter, and t = wall thickness.
Notice that the hoop stress is exactly twice as large as the longitudinal
stress.