Which type of tank is designed to store liquids under pressure?

The type of tank specifically designed to store liquids under pressure is the pressure tank. Pressure tanks can handle the stress and strain of storing liquids at elevated pressures, which is necessary for certain processes where vaporization or preventing evaporation is crucial. These tanks are constructed with materials and engineering designs that allow them to safely contain liquids under pressure, thereby preventing leaks and potential hazards associated with pressurized fluids.

In contrast, fixed-roof tanks, horizontal tanks, and external floating roof tanks are typically employed for atmospheric or low-pressure storage and are not intended to handle the same level of pressure as a pressure tank. Fixed-roof tanks have a rigid roof structure, while horizontal and external floating roof tanks manage liquid storage with configurations that do not incorporate pressure control. Consequently, they are more suitable for different applications where pressure containment is not a requirement.