How do you calculate foam expansion?

The more air is introduced, the higher expansion ratio you get. For example: when a foam generator supplied with 100 litres of water + foam solution produces 1000 litres of foam, the expansion ratio is therefore 1000/100 = 10.

What is the ratio for high expansion foam?

between 200:1 and 1000:1
HI-EX foam concentrate can be used to produce foam with expansion ratios ranging typically between 200:1 and 1000:1 depending upon the type of generator and the operating pressure.

How do you calculate foam solution?

The formula for calculating the needed foam concentrate at a flammable liquid release is as follows: Area X Critical Application Rate (CAR) X Eduction Rate (ER) X 15 = Foam Concentrate Needed.

How does a high expansion foam system work?

The high expansion foam suppresses fire first by separating the fuel from the air, suffocating the flames and immediately preventing further combustion. The foam then cools the area on fi re and reduces evaporation of flammable vapours into the air.

How is foam volume calculated?

To calculate the density of a piece of foam, you divide the weight of the foam by its width x height x length. If you measure in feet, density is expressed in weight per cubic foot. Say the density of a mattress is four pounds per cubic foot.

What is foam ratio?

Low expansion foams are considered to be those foams with an expansion ratio of 12:1 when mixed with air. That is one volume if foam concentrate will create 12 volumes of foam. Low expansion foams are effective in controlling and extinguishing most flammable liquid (Class “B”) fires.

What is medium expansion foam ratio?

MEDIUM EXPANSION FOAM: Expansion ratio between 20 to 1 and 200 to 1. HIGH EXPANSION FOAM: Expansion ratio above 200 to 1. DILUTION RATE, MIXING RATE, OR PROPORTIONING RATE (correct amount of foam concentrate to be mixed with water): The amount is normally shown on the pail or drum of concentrate.

What is low medium and high expansion foam?

LOW EXPANSION FOAM: Foam aerated to an expansion ratio of between 2 to 1 and 20 to 1. MEDIUM EXPANSION FOAM: Expansion ratio between 20 to 1 and 200 to 1. HIGH EXPANSION FOAM: Expansion ratio above 200 to 1.

How do you rate high density foam?

In the case of foam, it is measured in pounds per cubic foot (PCF). In other words, the density of foam is expressed by measuring the weight of a single cubic foot of foam material. As an example, consider a foam layer that weighs 100 pounds and measures 25 cubic feet in total.

How is foam density calculated?

What is low and high expansion foam?

Low-expansion foam expands less than 20 times when properly proportioned and agitated with air. The normal expansion range for low-expansion foams is usually 8 to 12 times. High-expansion foam is usually formed by blowing air through a solution-wetted netting or wire mesh.

What is the difference between high expansion and low expansion foam?

High Expansion foam has two components stored in separate tanks until mixed at the time of spraying. After spraying, it typically cures in less than 2 minutes. Low expansion foam comes in a single tank or container, and relies on moisture in the air to cure, usually in about 20 minutes.