A high expansion foam generator is a fire suppression device which is designed to produce large volumes of foam. It is used to fight fires in industrial and commercial environments. Typically, high expansion foam is used to reduce the intensity of fires and to control vapors released during a gas spill. The fire suppressant is also commonly used to protect flammable liquid facilities and aircraft hangars.

There are two main types of high expansion generators. The aspirated type uses a water motor to power a fan that forces the air through a screen. This air then expands the foam solution.

The other type uses a foam concentrate, which is mixed with water. The concentrated foam is then sprayed into a stainless steel screen to expand it into millions of tiny bubbles. Once this process is complete, the foam solution is then discharged.

High expansion foam generators are available in a range of output capacities. Depending on the generator, the output can vary from a nominal 5 litres per minute up to a maximum of 1000 litres per minute.

High expansion generators are usually part of a fixed fire protection system that also includes foam concentrate and a proportioning / admixing system. They can be installed vertically or horizontally.

High expansion foam generators are available for fire protection applications, including flammable liquid stores, warehouses, and tunnels. Generally, the generators are able to maintain performance at high back pressures.

High expansion generators are also manufactured with corrosion resistant pipework. These units are CE marked and are suitable for offshore and marine applications.