The foam is used in fire fighting by manual, portable, and stationary extinguishing systems, it is primarily used to fight flammable and flammable liquids fires, and the American Fire Protection Foundation issues many standard specifications and guidelines that address the different applications of the foam in fire fighting such as the protection of tanks and dams Preventing the spread of flammable and flammable liquids, as well as protection from the risks of fuel leakage from aircraft, protection of aircraft hangars, places for storing liquids, and different types of foam in terms of chemical composition, and this leads to different rates of foam discharge necessary for extinguishing, as well as the ability to suit the use in protecting types Certain liquid fuels, and the foam may be used with dry chemical powder, which provides a solution for both two-dimensional and three-dimensional scenarios for fuel leakage fires. The foam is formed by mixing the foam core with water in a specific proportion, and this is done by different types of manual mixing devices, or Portable, or stationary, several different foam discharging devices are available such as: sprinklers, nozzles, and an extent The foam is raised, and the low diffusion foam is used to extinguish fires resulting from leakage of flammable or flammable liquids, and tank fires, and this is done by forming a coherent blanket of foam that cools the burning surfaces, and that blanket can prevent the emission of fuel fumes for some time depending on the stability and depth of the foam on Inflamed surfaces, and that blanket is removed after an appropriate period of time, and this blanket has no effect on the product that it comes into contact with, and the foam can also be used to contain weakening or stopping the emission of inflammable fumes from the surfaces of unburned liquids and solid materials, in addition to the possibility of using it to fill the gaps And areas where toxic or flammable gases can collect, and in addition to the above, foam plays an important role in the operations of supplying aircraft with fuel and providing maintenance services, due to the possibility of a large fuel leakage due to an accident or malfunction, and it is also used in the applications of storing flammable liquids. Others use medium and high diffusion foam in filling places, as they stop the transfer of heat by convection currents and prevent the fire from reaching the necessary air The water content of these types of foam cools the burning surfaces and reduces the concentration of oxygen surrounding the surface by displacing it with water vapor, and these types of foam are also used to contain incidents of liquefied natural gas leakage, as they help to disperse the cloud of fumes resulting from this leakage. The foam that consists of solutions of low surface tension in extinguishing fires of class (A), and in this case the aqueous solution discharged from the foam exposes the flammable solids to wetness and cools their surfaces, and there are several reasons.
It may lead to the defective performance of the foam as an extinguishing medium unless these reasons are taken into account during the design of the system, as the foam may be subjected to decomposition and its water content will evaporate upon exposure to heat and flame. Hence, adequate volume and appropriate vacuum rates must be used on the burning surfaces to offset this effect, as well as The foam is considered unstable and therefore liable to dissolve easily when exposed to mechanical and physical forces (such as using a hose flush). The foam is subjected to severe decomposition when used with some other extinguishing media. Air turbulence or violent emission of combustion gases may lead to deflection of the foam from the area Combustion, and there are many types of foam concentrates available in the market, and these types differ in terms of chemical composition, mixing ratio, types of risks that are used to protect them in addition to the type of system used to empty the foam, and the following are the most common types available in the market:

Aqueous Film-Forming Foam (AFFF) -1.

Type: synthetic foam concentrates
Mixing ratio: 1%, 3%, 6%
• Diffusion Ratio Classification: Low Diffusion Foam
• Features:
It has a low viscosity
It is characterized by the speed of spreading and the ability to be flat on surfaces
– It forms a layer of aqueous solution underneath the foam, and maintains that layer floating on the hydrocarbon fuel surfaces to help quench the smoldering fumes and cool the fuel surface
The aqueous solution layer has the ability to spread on surfaces that are partly covered with foam
– This layer of aqueous solution is able to maintain its properties in case it is subjected to damage by mechanical or physical force (such as using water hoses or the like).
– Very suitable for fires caused by leaks of aviation fuel, due to the rapid spread of kerosene on the surface of fuel
It does not require advanced vacuum devices due to its ability to form quickly and easily
Can be used with dry chemical extinguishing agent

Alcohol Resistant Aqueous Film-Forming Foam (AR-AFFF) -2.

Type: synthetic foam concentrates.
Mixing ratio: 1×3%, 3×3%, 3×6%
• Diffusion Ratio Classification: Low Diffusion Foam
Features:
– It has the same features as the AFFF Foam Concentrate
– Suitable for use with polar solvents, soluble fuels or mixing with water, as it forms a gel-like floating mass on the surface of the fuel so that this mass allows foam to form on the surfaces of these fuels

Protein (P) Foaming Agent-3.

Type: Organic foam concentrates
Mixing ratio: 3%, 6%
• Diffusion Ratio Classification: Low Diffusion Foam
Features:
– It produces sticky foam with high density, high stability, high temperature resistance, and good re-ignition resistance
– It produces foam that has less resistance to degradation by exposure to saturated fuel than other foam concentrates such as (AFFF) and Flouroprotein).
It produces non-toxic foam and is biodegradable

Fluoroprotein (FP) Foaming Agent-4.

Type: Organic foam concentrates
Mixing ratio: 3%, 6%
• Diffusion Ratio Classification: Low Diffusion Foam
• Features:
Contains fluorine particles, which give the foam a protective layer from fuel pollution
Suitable for sub-fuel injection
Suitable for use with nozzles and foam guns
Suitable for deep ore fires
– More compatible with dry chemical powder extinguishing agent than other protein based foam concentrates

Film-Forming Fluoroprotein (FFFP) -5.

Type: Organic foam concentrates
Mixing ratio: 3%, 6%
• Diffusion Ratio Classification: Low Diffusion Foam
• Features:
– Contains fluorine molecules that give the foam a protective layer from fuel pollution in addition to its ability to form a layer of aqueous solution on the surface of most hydrocarbon fuels
It is characterized by the speed of spreading and the ability to be flat on surfaces
– The aqueous solution layer is able to maintain its properties in the event of damage caused by mechanical or physical force (such as using water hoses or the like)
Suitable for use with sprinklers due to its ability to form quickly and easily
It is characterized by having a higher capacity than other protein-based foam concentrates in terms of re-ignition resistance

High Expansion Foam-6.
Type: synthetic foam concentrates
Mixing ratio: 2%
• Diffusion ratios classification: widespread foam
• Features:
– It is used to contain and extinguish Class (A) and some Class (B) fires
– It is commensurate with the total immersion of the fires that occur in narrow places or those that are difficult to reach, in addition to the processes of displacement of fumes, heat and smoke
Can be used with automatic water sprinkler extinguishing systems
It can be used to contain fires resulting from liquefied natural gas leaks, as well as reduce the evaporation rates of the leaked gas
The process of producing and generating foam for fire fighting requires three separate processes, each of which consumes an amount of energy, namely:

1. The mixing process
2. The stage of generating foam
3. The method of distribution

There are many types of water foaming mixing devices, including the following types:

1. Nozzle Eductor
It is a device that includes a venture to draw the foam core through a short tube and / or a flexible tube connected to the foam source.

2. In-Line Eductor Mixer
It is a finch mixing device that measures the amount of foam concentrate to be mixed with water in a fixed or variable ratio and injected into the flowing water at a point located between the water source and the discharge nozzle or any other foam discharging device.

3. Foam mixing system using (Around the Pump Proportioner).
It is a system that uses a finch mixer installed on a side line connecting the outlet and the inlet of the water pump, with a fixed or variable size (Orifice) nozzle to withdraw the foam concentrate from a container or tank and mix it with water, and inject them into the inlet of the water pump.
4. Pressure Proportioning Tank.
It is a reservoir for the foam center that does not contain inside it an expandable membrane (Bladder), so that it depends in displacing a foam center of no less than 1.15 specific weight on the flow of water inside the tank through the nozzle (Orifice), with the aim of mixing the displacement amount from the foam center with the water flowing Line water with constant mixing ratio through another orifice.
5. Foam mixing system by connecting water and foam pumps (Coupled Water Motor-Pump Proportioner).
It is a system that contains a water turbine that is installed on the water line and mechanically connected to a pump to inject the foam center, so that the foam core is withdrawn by the pump and then mixed with water at the inlet of the water turbine, and the mixing efficiency depends on the correct design of the mechanical connection system designed for this purpose.
6. Foam mixing systems by balancing water pressure and foam center (Balanced Pressure Proportioner)
It is a system for mixing foam concentrate with water that uses a foam concentrate tank of the stretch membrane type (Bladder Tank) or foam concentrate injection students in addition to several valves to achieve balance in pressure between the foam center and the water when the two openings enter the finish mixer installed on the foam solution pipe, So that an Orifice nozzle is installed inside the mixer to determine the quantity flowing from the foam center to it in order to achieve the required mixing ratio.
7. Variable Orifice / Variable Flow Demand Proportioner (Variable Orifice, Variable Flow Demand Proportioner)
It is a mixing system that works by direct injection of the foam center, using a meter to measure the flow rate of water and the foam center, in addition to a control system in the injection pump of the foam center with variable speed.
There are also several foaming equipment and systems which include the following types:

1. Foam Equipment
Hose Line Foam Nozzle
It is a nozzle that contains a venture to withdraw the foam core by means of a short tube and / or a flexible tube connected to the source of the foam center, mixing it with water to turn it into a foamy solution and then discharging it as foam.
Foam and Foam – Water Monitors
Fixed Monitor
It is a device that delivers high flows of foam to the target area, covering it with foam, so that it is installed on a stable base with a high level or with a ground level.
Portable Monitor Guns
It is a device that delivers high flows of foam to the target area covering it with foam, so that it is fixed on
A base that can be moved or on a set of wheels to facilitate transportation to the place of fire.
High Back-Pressure Foam Maker
They are foam generating devices that use finchor theory to draw air into a foaming solution and create foam under high pressure.
High Expansion Foam-Generating Devices
There are two methods for generating such a type of foam used in fire fighting, one of them uses a modified venture effect with the flow of the drawn air, while the other uses a blower with a mesh screen to generate the foam in its final form, and the foam generated using the second method contains How much of the remaining kinetic energy can escape through large tubes and corridors.
Water Fog or Spray Nozzle
It is a foam hose nozzle or a fixed foam generator designed to draw air and is connected to a source of foaming solution, and there are several types of adjustable spray or water mist nozzles for use in portable systems, so that they generate foam that is stable in terms of quality and suitable in terms of properties, and that is. When supplied with certain types of foaming concentrates.

2. Foam-Generating Equipment and Systems
Open Dip Tank, Quench Tank System
This system consists of a small foam generator of a type that draws air so that it is supplied with water through a water line, while an induction foam center is drawn into this generator, and then the foam is discharged into a mixing box, which in turn acts as a surface dispenser used to spread Foam the surface gently
Foam Chambers for Large Storage Tanks
Prevention of large external fuel tank fires requires the installation of several foam dump chambers with the foam generators on the tank wall just below the Curb Angle and with equal intervals. These foam generators are connected to lines on the ground to supply the foam solution to all generators simultaneously, And when the flammable materials contained in the tank ignite, and the breakable insulation at the outlet of the vacuum chamber works to prevent the vapors of the flammable materials from entering the foam pipes, and these insulators are designed so that they are broken under the influence of the pressure of the flowing foam, and the network that is installed at the inlet to draw air into The foam generator is to prevent blockage by external materials such as bird’s nest components, and a swing-type connection is installed at the bottom of the foam solution entry pipe at the ground level to prevent a break in the pipe when an explosion occurs before the fire in the tank.
Internal Tank Foam Distributing Devices
They are devices developed to gently spread foam over the burning fuel surface inside the tank from one point regardless of the fuel surface level inside the tank, and some types of alcohol-resistant foam concentrates require the use of such devices.
Central Foam House Distributing Systems
They are systems that include a space containing a reservoir for the foam center and a device for mixing foam of the automatic type or the type that works by achieving pressure equilibrium between the foam center and the water, where the foam discharging chambers and the foam generators are supplied in the burning tank with the foam solution at an appropriate pressure from that space through a piping system. Controlled by a number of valves suitable for this purpose.
Intermediate Back-Pressure System
They are systems similar to the central foam distribution system, but use strong and well-fixed pipes in the tank wall to deliver the foam, which act as a support that prevents dentation of the tank under the influence of heat, and this system also uses fire trucks to mix the foam center and water and pump the foam solution to the pipes outside the containment wall (Dike The burning tank.
Subsurface Foam-Injection Systems
They are systems that inject foam against the fuel column pressure in the tank using high inlet pressure foam generators.
Portable Foam Devices for Tank Protection
Portable foam cannons with high flow rates are used to direct the flow of foam from the edges of tanks with open surfaces so that the foam falls on the burning area, noting that these devices dissipate the foam due to the occasional winds and upward currents of fire, as well as the inability to install the device in locations of advantage. Relative.
Foam Water Sprinkler System
It is a piping network that includes automatic sprinklers, nozzles, and other evacuation devices. This network is connected to a water source and foam center.

High Expansion Foam System
High diffusion foam is defined as the accumulation of foam bubbles resulting from the mechanical expansion process of the foaming solution with air or any other gas with a range of expansion ratios located between approximately 20: 1 to 1: 1000, and this type of foam concentrate is used in total immersion and extinguishing systems. Positional, in addition to portable systems.
Compressed Air Foam System
It is a system that uses vacuum devices or hoses for compressed air foam, so that those devices or hoses are attached to the pipes that transport the foam from the mixing chambers.The foam is used in fire fighting by manual, portable, and stationary extinguishing systems, it is primarily used to fight flammable and flammable liquids fires, and the American Fire Protection Foundation issues many standard specifications and guidelines that address the different applications of the foam in fire fighting such as the protection of tanks and dams Preventing the spread of flammable and flammable liquids, as well as protection from the risks of fuel leakage from aircraft, protection of aircraft hangars, places for storing liquids, and different types of foam in terms of chemical composition, and this leads to different rates of foam discharge necessary for extinguishing, as well as the ability to suit the use in protecting types Certain liquid fuels, and the foam may be used with dry chemical powder, which provides a solution for both two-dimensional and three-dimensional scenarios for fuel leakage fires. The foam is formed by mixing the foam core with water in a specific proportion, and this is done by different types of manual mixing devices, or Portable, or stationary, several different foam discharging devices are available such as: sprinklers, nozzles, and an extent The foam is raised, and the low diffusion foam is used to extinguish fires resulting from leakage of flammable or flammable liquids, and tank fires, and this is done by forming a coherent blanket of foam that cools the burning surfaces, and that blanket can prevent the emission of fuel fumes for some time depending on the stability and depth of the foam on Inflamed surfaces, and that blanket is removed after an appropriate period of time, and this blanket has no effect on the product that it comes into contact with, and the foam can also be used to contain weakening or stopping the emission of inflammable fumes from the surfaces of unburned liquids and solid materials, in addition to the possibility of using it to fill the gaps And areas where toxic or flammable gases can collect, and in addition to the above, foam plays an important role in the operations of supplying aircraft with fuel and providing maintenance services, due to the possibility of a large fuel leakage due to an accident or malfunction, and it is also used in the applications of storing flammable liquids. Others use medium and high diffusion foam in filling places, as they stop the transfer of heat by convection currents and prevent the fire from reaching the necessary air The water content of these types of foam cools the burning surfaces and reduces the concentration of oxygen surrounding the surface by displacing it with water vapor, and these types of foam are also used to contain incidents of liquefied natural gas leakage, as they help to disperse the cloud of fumes resulting from this leakage. The foam that consists of solutions of low surface tension in extinguishing fires of class (A), and in this case the aqueous solution discharged from the foam exposes the flammable solids to wetness and cools their surfaces, and there are several reasons.
It may lead to the defective performance of the foam as an extinguishing medium unless these reasons are taken into account during the design of the system, as the foam may be subjected to decomposition and its water content will evaporate upon exposure to heat and flame. Hence, adequate volume and appropriate vacuum rates must be used on the burning surfaces to offset this effect, as well as The foam is considered unstable and therefore liable to dissolve easily when exposed to mechanical and physical forces (such as using a hose flush). The foam is subjected to severe decomposition when used with some other extinguishing media. Air turbulence or violent emission of combustion gases may lead to deflection of the foam from the area Combustion, and there are many types of foam concentrates available in the market, and these types differ in terms of chemical composition, mixing ratio, types of risks that are used to protect them in addition to the type of system used to empty the foam, and the following are the most common types available in the market:

Aqueous Film-Forming Foam (AFFF) -1.

Type: synthetic foam concentrates
Mixing ratio: 1%, 3%, 6%
• Diffusion Ratio Classification: Low Diffusion Foam
• Features:
It has a low viscosity
It is characterized by the speed of spreading and the ability to be flat on surfaces
– It forms a layer of aqueous solution underneath the foam, and maintains that layer floating on the hydrocarbon fuel surfaces to help quench the smoldering fumes and cool the fuel surface
The aqueous solution layer has the ability to spread on surfaces that are partly covered with foam
– This layer of aqueous solution is able to maintain its properties in case it is subjected to damage by mechanical or physical force (such as using water hoses or the like).
– Very suitable for fires caused by leaks of aviation fuel, due to the rapid spread of kerosene on the surface of fuel
It does not require advanced vacuum devices due to its ability to form quickly and easily
Can be used with dry chemical extinguishing agent

Alcohol Resistant Aqueous Film-Forming Foam (AR-AFFF) -2.

Type: synthetic foam concentrates.
Mixing ratio: 1×3%, 3×3%, 3×6%
• Diffusion Ratio Classification: Low Diffusion Foam
Features:
– It has the same features as the AFFF Foam Concentrate
– Suitable for use with polar solvents, soluble fuels or mixing with water, as it forms a gel-like floating mass on the surface of the fuel so that this mass allows foam to form on the surfaces of these fuels

Protein (P) Foaming Agent-3.

Type: Organic foam concentrates
Mixing ratio: 3%, 6%
• Diffusion Ratio Classification: Low Diffusion Foam
Features:
– It produces sticky foam with high density, high stability, high temperature resistance, and good re-ignition resistance
– It produces foam that has less resistance to degradation by exposure to saturated fuel than other foam concentrates such as (AFFF) and Flouroprotein).
It produces non-toxic foam and is biodegradable

Fluoroprotein (FP) Foaming Agent-4.

Type: Organic foam concentrates
Mixing ratio: 3%, 6%
• Diffusion Ratio Classification: Low Diffusion Foam
• Features:
Contains fluorine particles, which give the foam a protective layer from fuel pollution
Suitable for sub-fuel injection
Suitable for use with nozzles and foam guns
Suitable for deep ore fires
– More compatible with dry chemical powder extinguishing agent than other protein based foam concentrates

Film-Forming Fluoroprotein (FFFP) -5.

Type: Organic foam concentrates
Mixing ratio: 3%, 6%
• Diffusion Ratio Classification: Low Diffusion Foam
• Features:
– Contains fluorine molecules that give the foam a protective layer from fuel pollution in addition to its ability to form a layer of aqueous solution on the surface of most hydrocarbon fuels
It is characterized by the speed of spreading and the ability to be flat on surfaces
– The aqueous solution layer is able to maintain its properties in the event of damage caused by mechanical or physical force (such as using water hoses or the like)
Suitable for use with sprinklers due to its ability to form quickly and easily
It is characterized by having a higher capacity than other protein-based foam concentrates in terms of re-ignition resistance

High Expansion Foam-6.
Type: synthetic foam concentrates
Mixing ratio: 2%
• Diffusion ratios classification: widespread foam
• Features:
– It is used to contain and extinguish Class (A) and some Class (B) fires
– It is commensurate with the total immersion of the fires that occur in narrow places or those that are difficult to reach, in addition to the processes of displacement of fumes, heat and smoke
Can be used with automatic water sprinkler extinguishing systems
It can be used to contain fires resulting from liquefied natural gas leaks, as well as reduce the evaporation rates of the leaked gas
The process of producing and generating foam for fire fighting requires three separate processes, each of which consumes an amount of energy, namely:

1. The mixing process
2. The stage of generating foam
3. The method of distribution

There are many types of water foaming mixing devices, including the following types:

1. Nozzle Eductor
It is a device that includes a venture to draw the foam core through a short tube and / or a flexible tube connected to the foam source.

2. In-Line Eductor Mixer
It is a finch mixing device that measures the amount of foam concentrate to be mixed with water in a fixed or variable ratio and injected into the flowing water at a point located between the water source and the discharge nozzle or any other foam discharging device.

3. Foam mixing system using (Around the Pump Proportioner).
It is a system that uses a finch mixer installed on a side line connecting the outlet and the inlet of the water pump, with a fixed or variable size (Orifice) nozzle to withdraw the foam concentrate from a container or tank and mix it with water, and inject them into the inlet of the water pump.
4. Pressure Proportioning Tank.
It is a reservoir for the foam center that does not contain inside it an expandable membrane (Bladder), so that it depends in displacing a foam center of no less than 1.15 specific weight on the flow of water inside the tank through the nozzle (Orifice), with the aim of mixing the displacement amount from the foam center with the water flowing Line water with constant mixing ratio through another orifice.
5. Foam mixing system by connecting water and foam pumps (Coupled Water Motor-Pump Proportioner).
It is a system that contains a water turbine that is installed on the water line and mechanically connected to a pump to inject the foam center, so that the foam core is withdrawn by the pump and then mixed with water at the inlet of the water turbine, and the mixing efficiency depends on the correct design of the mechanical connection system designed for this purpose.
6. Foam mixing systems by balancing water pressure and foam center (Balanced Pressure Proportioner)
It is a system for mixing foam concentrate with water that uses a foam concentrate tank of the stretch membrane type (Bladder Tank) or foam concentrate injection students in addition to several valves to achieve balance in pressure between the foam center and the water when the two openings enter the finish mixer installed on the foam solution pipe, So that an Orifice nozzle is installed inside the mixer to determine the quantity flowing from the foam center to it in order to achieve the required mixing ratio.
7. Variable Orifice / Variable Flow Demand Proportioner (Variable Orifice, Variable Flow Demand Proportioner)
It is a mixing system that works by direct injection of the foam center, using a meter to measure the flow rate of water and the foam center, in addition to a control system in the injection pump of the foam center with variable speed.
There are also several foaming equipment and systems which include the following types:

1. Foam Equipment
Hose Line Foam Nozzle
It is a nozzle that contains a venture to withdraw the foam core by means of a short tube and / or a flexible tube connected to the source of the foam center, mixing it with water to turn it into a foamy solution and then discharging it as foam.
Foam and Foam – Water Monitors
Fixed Monitor
It is a device that delivers high flows of foam to the target area, covering it with foam, so that it is installed on a stable base with a high level or with a ground level.
Portable Monitor Guns
It is a device that delivers high flows of foam to the target area covering it with foam, so that it is fixed on
A base that can be moved or on a set of wheels to facilitate transportation to the place of fire.
High Back-Pressure Foam Maker
They are foam generating devices that use finchor theory to draw air into a foaming solution and create foam under high pressure.
High Expansion Foam-Generating Devices
There are two methods for generating such a type of foam used in fire fighting, one of them uses a modified venture effect with the flow of the drawn air, while the other uses a blower with a mesh screen to generate the foam in its final form, and the foam generated using the second method contains How much of the remaining kinetic energy can escape through large tubes and corridors.
Water Fog or Spray Nozzle
It is a foam hose nozzle or a fixed foam generator designed to draw air and is connected to a source of foaming solution, and there are several types of adjustable spray or water mist nozzles for use in portable systems, so that they generate foam that is stable in terms of quality and suitable in terms of properties, and that is. When supplied with certain types of foaming concentrates.

2. Foam-Generating Equipment and Systems
Open Dip Tank, Quench Tank System
This system consists of a small foam generator of a type that draws air so that it is supplied with water through a water line, while an induction foam center is drawn into this generator, and then the foam is discharged into a mixing box, which in turn acts as a surface dispenser used to spread Foam the surface gently
Foam Chambers for Large Storage Tanks
Prevention of large external fuel tank fires requires the installation of several foam dump chambers with the foam generators on the tank wall just below the Curb Angle and with equal intervals. These foam generators are connected to lines on the ground to supply the foam solution to all generators simultaneously, And when the flammable materials contained in the tank ignite, and the breakable insulation at the outlet of the vacuum chamber works to prevent the vapors of the flammable materials from entering the foam pipes, and these insulators are designed so that they are broken under the influence of the pressure of the flowing foam, and the network that is installed at the inlet to draw air into The foam generator is to prevent blockage by external materials such as bird’s nest components, and a swing-type connection is installed at the bottom of the foam solution entry pipe at the ground level to prevent a break in the pipe when an explosion occurs before the fire in the tank.
Internal Tank Foam Distributing Devices
They are devices developed to gently spread foam over the burning fuel surface inside the tank from one point regardless of the fuel surface level inside the tank, and some types of alcohol-resistant foam concentrates require the use of such devices.
Central Foam House Distributing Systems
They are systems that include a space containing a reservoir for the foam center and a device for mixing foam of the automatic type or the type that works by achieving pressure equilibrium between the foam center and the water, where the foam discharging chambers and the foam generators are supplied in the burning tank with the foam solution at an appropriate pressure from that space through a piping system. Controlled by a number of valves suitable for this purpose.
Intermediate Back-Pressure System
They are systems similar to the central foam distribution system, but use strong and well-fixed pipes in the tank wall to deliver the foam, which act as a support that prevents dentation of the tank under the influence of heat, and this system also uses fire trucks to mix the foam center and water and pump the foam solution to the pipes outside the containment wall (Dike The burning tank.
Subsurface Foam-Injection Systems
They are systems that inject foam against the fuel column pressure in the tank using high inlet pressure foam generators.
Portable Foam Devices for Tank Protection
Portable foam cannons with high flow rates are used to direct the flow of foam from the edges of tanks with open surfaces so that the foam falls on the burning area, noting that these devices dissipate the foam due to the occasional winds and upward currents of fire, as well as the inability to install the device in locations of advantage. Relative.
Foam Water Sprinkler System
It is a piping network that includes automatic sprinklers, nozzles, and other evacuation devices. This network is connected to a water source and foam center.

High Expansion Foam System
High diffusion foam is defined as the accumulation of foam bubbles resulting from the mechanical expansion process of the foaming solution with air or any other gas with a range of expansion ratios located between approximately 20: 1 to 1: 1000, and this type of foam concentrate is used in total immersion and extinguishing systems. Positional, in addition to portable systems.
Compressed Air Foam System
It is a system that uses vacuum devices or hoses for compressed air foam, so that those devices or hoses are attached to the pipes that transport the foam from the mixing chambers.