The foam chamber is typically used to apply low-expansion foam solution onto the surface of liquids stored in storage tanks, quickly creating a secure foam blanket. The most common structures these are installed into are vertical fixed (cone) roof storage tanks, either with or without internal floating roofs.
Systems are usually designed to NFPA 11 (Standard for Low-, Medium-, and High-Expansion Foam), the foam solution is applied across the complete surface area of the liquid. Foam chambers are defined by NFPA 11 as Type II Discharge Outlets for delivering foam to the surface of a flammable liquid. They can be used in conjunction with inline foam inductors, balanced-pressure foam proportioning systems, bladder tank proportioners or foam tenders.