What rate of static pressure must a storage tank withstand?

The correct answer is based on industry standards that dictate the design and pressure ratings for storage tanks. A storage tank must be engineered to withstand a minimum static pressure that is determined by the height of the liquid column above the outlet. This requirement ensures that the tank can handle the pressure generated by the liquid it contains up to the fill plate or vent without risking structural failure or leaks.

Specifically, the correct guideline stipulates that the tank must support a pressure that is at least 1.5 times greater than the pressure resulting from the height of the liquid column, which accounts for various factors such as the density of the liquid and the height it is maintained within the tank. This approach provides a margin of safety to ensure that normal variations in temperature, liquid density, and other operational conditions do not lead to pressure that exceeds the tank's capabilities.

Additionally, the standard mandates a minimum baseline of 3 PSI to address any potential discrepancies that might occur during certain operational scenarios, ensuring the tank's integrity under those conditions. Therefore, the correct answer reflects both the necessary safety factor relative to the height of the tank’s contents and a minimum pressure threshold that the tank must withstand to comply with safety regulations.