- Foam Fire Protection System Definition: A foam fire protection system is defined as a fire suppression system that uses foam to put out fires, particularly effective for oil fires.
- Foam Concentration Importance: Proper mixing of foam concentrate with air and water is crucial for creating an effective foam blanket to suppress fires.
- Application in Oil Fires: Foam systems are primarily used to fight oil fires, protecting oil tanks and preventing the fire from spreading to nearby areas.
- Key Components: Essential parts of the system include a foam concentrate tank, proportioning devices, automatic valves, and foam producers.
- Design Standards: The system should comply with NFPA-11 regulations, ensuring the correct foam concentration and pump capacity for effective fire suppression.
A Foam Fire Protection System is a fire suppression system. Its success mainly depends on properly mixing foam concentrate with air and water to create a uniform foam blanket that extinguishes flames.
Back Ground of Foam Fire Protection System
Water is known for suppressing fires, but unfortunately not best in all the cases. Water is not effective on an oil fire, and can be of no use during emergency. To suppress oil fire foam is reliable to use, since it prevent the direct contact of fire with oxygen, resulting in suppression of the combustion.
Application of Foam Fire Protection System
A Foam Fire Protection System is designed to counter oil fires, including light diesel oil and heavy furnace oil fires. It is often used to protect and extinguish fires in oil tanks.
The foam system serves two purposes: it extinguishes fires in oil tanks and cools the tank from the outside using circular pipelines. This helps prevent the fire from spreading to nearby tanks.
Foam Fire Protection System Comprises of
The concentration of the foam is an important factor in this system. It comprises of foam concentration tank, proportioning device, automatic controlling valves, controlling panel, foam producer, discharge outlet etc.
- System Tank – for storing the foam, tank can be of cylindrical vertical or horizontal type stainless steel.
- Proportioning Devices – for discharging the sufficient amount of foam- concentrate into the spray-water based on specific requirement. These devices are sized and designed keeping in mind the minimum loss of pressure.
- Foam-chambers.
- Automatic Foam Protection system mainly includes all areas where fuel oil storage tanks are built.
- Apart from this, it covers all the sensitive areas of the power plant where hydrant system and spray system do not perform fairly.
Foam Fire Protection System Design Principles
Given below are the design basics which need to be given due importance before installing Foam system:
- The fixed foam system operates automatically with help from a fire detection system around the tank. It forms a network of pipes near all fuel oil storage tanks.
- The complete system should be designed as per NFPA-11 regulations.
- Concentration of foam is a very important factor and it should be 100 % AFFF type, and stored in a tank of double of its capacity and it is discharged through a foam pump of capacity of 200 %.
- The minimum effective capacity of each foam concentrate tank and foam pumps should be designed for the protection of one largest fuel oil tank at its design capacity for a minimum duration of 60 minutes.
- Automatic foam protection system covers an area of oil storage tank and its surroundings. As fire detection system sense any smoke in the surroundings, automatic foam protection system starts working automatically.
- Foam concentrate is drawn by two foam inductors, each with 100% capacity—one motor-driven and one diesel-engine-driven.
- Special attention shall be given for foam pumps material and the complete system should be designed as per the TAC norms.
- The minimum effective capacity of foam concentrate tank should keep in consideration while designing and there should be an extra margin of 10 % over the calculated capacity.
- The material used for making tanks shall be of carbon steel of Grade ‘B’ and there should be inner lining of 2 mm of FRP.
- LDO tanks should be well equipped with foam proportioner.
- Water required for foam system is supplied by hydrant system mains.
- Supply line of oil tanks should be equipped with automatic solenoid at the upstream of foam proportioner.
- In foam protection system, the network of pipelines has been done over the ground on RCC foundation.
- Foam carrying pipelines should be of stainless steel.
- For fixed roof type tanks, foam application rate should be 3% and foam solution shall be 6 lpm/sq.m.
- Special components like non-return valves, strainers and isolation valves of pumps etc. should be used to avoid mixing of water with foam concentration.
Strainers should be used at the water inlet point so that raw impurities could be captured there and non-return valve in the pipelines avoids mixing of water with foam.
