For the design of internal-pressure cylindrical vessels, the API-ASME Code for Unified Pressure Vessels recommends the following equations for determining the minimum wall thickness when extreme operating pressures are not involved:
A cylindrical storage tank is to have an ID of 12 ft and a length of 36 ft. The seams will be welded, and the material of construction will be plain carbon steel (0.15 percent 0. The maximum working pressure in the tank will be 100 psig, and the maximum temperature will be 25°C. No corrosion problems are anticipated. On the basis of the preceding equations, estimate the necessary wall thickness.