What type of foam does not require an aeration device?

AFFF foam, or Aqueous Film-Forming Foam, is designed to suppress flammable liquid fires effectively without needing an aeration device. This type of foam creates a blanket of liquid that forms a film on top of the burning liquid, cutting off the oxygen and suppressing the fire. Its ability to work without aeration allows for quicker deployment and effectiveness in various firefighting situations where immediate suppression is crucial.

In contrast, other types of foam such as low-expansion, protein, and high-expansion foam rely on aeration to generate bubbles, which create a stable foam blanket. Low-expansion foams typically require a certain level of air infusion to achieve the correct expansion ratio. Protein foam also necessitates aeration to enhance its effectiveness, while high-expansion foam is designed to fill large spaces and again requires an aeration device to create the necessary volume of bubbles for effectiveness. Therefore, AFFF foam's unique formulation enables it to operate effectively without additional equipment.