What happens to a tank when it becomes waterlogged?

When a tank becomes waterlogged, it essentially has a reduced capacity to function as intended due to the lack of sufficient air cushion above the water level. In this condition, the air that typically provides the necessary elasticity and pressure in the system gets displaced by water. This displacement leads to a situation where both air and water are present, but the air is unable to play its critical role in generating back pressure.

Back pressure is crucial for many functions, such as maintaining water flow and ensuring that the system remains efficient during operations. When the tank is waterlogged, there’s an inability to create appropriate pressure conditions because the air is not effectively compressible within the water. Therefore, the lack of sufficient air to generate the necessary pressure directly correlates to the statement that air and water cannot generate back pressure when the tank is waterlogged.

The other options do not accurately describe the effects of waterlogging in a tank. Efficient generation of back pressure cannot occur when air volume is compromised, storing only air would not be the case if the tank is filled with water, and chemical treatment improvements do not directly link to the state of being waterlogged.