Foam Expansion Nozzle

forede® Foam Expansion Nozzle also known as Medium Expansion Foam Nozzle (MEF Nozzle) is a specialized firefighting appliance designed to generate fire-suppressing foam by mechanically aspirating air into a stream of foam solution (a mixture of water and foam concentrate). Its core function is to produce foam with an expansion ratio typically falling between 20:1 and 200:1. This means for every 1 unit volume of foam solution entering the nozzle, it outputs between 20 and 200 unit volumes of finished foam. Physically, MEF nozzles often resemble modified fog nozzles but incorporate critical design features like an aspirating chamber (sometimes a cage-like structure at the tip) or specific internal baffling. As the pressurized foam solution passes through this chamber, it creates a venturi effect or turbulence that draws in and intimately mixes large quantities of ambient air. This process forms bubbles, creating the characteristic medium expansion foam. This foam is less fluid than low-expansion foam but significantly more so than the stiff, dry blocks of high-expansion foam, striking a unique balance crucial for its tactical applications.