How should foam concentrate be poured into the tank to minimize aeration?

Pouring foam concentrate slowly through the expansion dome hatch or down the center of the round tube is the best practice to minimize aeration. When foam concentrate is added slowly and directly into the tank, it allows the concentrate to mix with the water in a controlled manner. This reduces turbulence in the tank, which helps to limit the amount of air that gets incorporated into the foam solution.

Minimizing aeration is crucial because excessive air can affect the effectiveness of the foam production, leading to a less stable foam that might not perform well in extinguishing fires. The method specified allows for a more uniform mixture of the foam concentrate with the water, which is essential for creating a high-quality foam.

The other methods, such as pouring quickly through the side panel or directly into the water supply, can introduce more air into the system and create turbulence that compromises the foam's properties. Using a pressurized nozzle may also lead to improper mixing and increased aeration, as it could force the concentrate into the water too rapidly, preventing the desired mixing effect.