Think back to our warehouse scenario from the last post. The fire detection system has done its job, sounding the alarm and alerting everyone to the danger. But now what? This is where the second crucial layer of defence kicks in, fire suppression systems. These are the workhorses of fire safety, designed to contain and conquer a fire, limiting its spread and ultimately extinguishing the flames.
In Australia, where industrial activities are diverse and often involve significant fire risks, effective fire suppression is paramount. Imagine a food processing plant with flammable cooking oils, or a timber mill with highly combustible sawdust. Without robust suppression systems in place, a small ignition could quickly escalate into a major incident. Let’s delve into the vital role these systems play in protecting Australian industrial buildings.
The Necessity of Effective Fire Suppression
Once a fire has started, every second counts. Effective fire suppression is essential for several key reasons:
- Protecting Lives – By quickly controlling or extinguishing the fire, suppression systems provide more time for safe evacuation and reduce the risk of injuries or fatalities.
- Limiting Property Damage – Prompt suppression can significantly minimise the damage to buildings, equipment, and inventory, saving businesses from substantial financial losses.
- Preventing Spread – Suppression systems are designed to contain the fire to its area of origin, preventing it from spreading to other parts of the building or neighboring properties.
- Facilitating Firefighter Intervention – By reducing the intensity of the fire, suppression systems create safer conditions for firefighters to enter the building and complete the extinguishment.
- Ensuring Business Continuity – Minimising damage and downtime allows businesses to resume operations more quickly after a fire incident.
Distinction Between Active and Passive Fire Suppression
As we briefly touched on in the first blog post, fire suppression can be broadly categorized into two types: active and passive.
- Active Fire Suppression Systems – These are systems that actively work to extinguish or control a fire through the application of a suppressant agent, such as water, foam, or gas. They often require activation, either automatically or manually.
- Passive Fire Suppression – These measures focus on preventing the spread of fire and smoke through the use of fire-resistant materials and building design. Examples include fire-rated walls, fire doors, and fire dampers.
In this post, we’ll primarily focus on active fire suppression systems, as they are the direct combatants of a fire.
Common Active Fire Suppression Systems in Industrial Buildings
Industrial buildings utilize a variety of active fire suppression systems, each suited for different types of hazards and environments.
Sprinkler Systems, The Ubiquitous Water Warriors
Sprinkler systems are arguably the most common and widely used active fire suppression systems in industrial buildings across Australia. They are highly effective at controlling and extinguishing fires involving ordinary combustibles.
Different Types of Sprinkler Systems
While the basic principle is the same – discharging water onto a fire – there are different types of sprinkler systems designed for specific applications:
- Wet Pipe Systems – These are the most common type, where the pipes are constantly filled with water under pressure. When a sprinkler head is activated by heat, water is immediately discharged. They are simple, reliable, and cost-effective for most applications where freezing is not a concern.
- Dry Pipe Systems – In these systems, the pipes are filled with pressurized air or nitrogen instead of water. When a sprinkler head activates, the air pressure is released, allowing water to flow into the pipes and discharge. Dry pipe systems are used in areas where freezing temperatures might occur, such as unheated warehouses or cold storage facilities.
- Pre-Action Systems – These systems are a hybrid of wet and dry pipe systems. Water is held back from entering the pipes by a valve that requires both a fire detection event (like a smoke detector activation) and a sprinkler head activation before water is discharged. This helps to prevent accidental water damage in sensitive areas like data centers or archives.
- Deluge Systems – In these systems, all sprinkler heads in a protected area are open. When the system is activated by a fire detection system, a large volume of water is discharged simultaneously over the entire area. Deluge systems are typically used in high-hazard areas where a rapid and intense fire is likely, such as flammable liquid storage or processing areas.
Applications and Suitability
The suitability of a particular sprinkler system depends on factors like the type of materials being stored or processed, the temperature of the environment, and the potential for accidental water discharge.
Importance of Design, Installation, and Maintenance
Like fire detection systems, sprinkler systems must be properly designed, installed, and maintained according to Australian Standards (like AS 2118 series: Fire sprinkler systems). Incorrect design or poor maintenance can significantly compromise the system’s effectiveness. Regular inspections, testing, and maintenance are crucial to ensure that the system will operate reliably when needed.
Foam Systems, Tackling Flammable Liquid Fires
Fires involving flammable liquids require specialised suppression agents, and foam systems are highly effective in these situations. Foam works by creating a blanket over the fuel, smothering the fire, cooling the fuel surface, and preventing the release of flammable vapors.
Types of Foam Concentrates and Their Uses
Different types of foam concentrates are available, each designed for specific types of flammable liquids and application methods. These include:
- Aqueous Film-Forming Foam (AFFF) – Commonly used for hydrocarbon fuels like gasoline and jet fuel. WorkSafe recommendations
- Film-Forming Fluoroprotein (FFFP) – Similar to AFFF but with better burnback resistance.
- Alcohol-Resistant (AR) Foams – Used for polar solvents like alcohols and ketones, which can break down regular foams.
Design Considerations for Foam Suppression Systems
The design of a foam suppression system must take into account factors like the type and quantity of flammable liquid, the area to be protected, and the method of application (e.g., sprinklers, nozzles, monitors).
Environmental Aspects of Foam Use
It’s important to be aware of the environmental aspects of foam concentrates. Some older types of foam contained per- and polyfluoroalkyl substances (PFAS), which are persistent environmental contaminants. Newer, more environmentally friendly foam formulations are now available, and regulations regarding the use of PFAS-containing foams are evolving in Australia. (See above WorkSafe recommendations)
Gas Suppression Systems, Protecting Sensitive Equipment
In areas containing sensitive electronic equipment, such as data centers, telecommunication facilities, and control rooms, water-based suppression systems can cause significant damage. Gas suppression systems, also known as clean agent systems, use inert or synthetic gases to extinguish fires without leaving behind residue.
Inert Gas Systems
These systems use naturally occurring gases like argon, nitrogen, or carbon dioxide to reduce the oxygen level in the protected area below the point where combustion can be sustained. They are environmentally friendly but require higher concentrations, which can pose a risk to occupants if not properly managed.
Synthetic Gas Systems
These systems use manufactured chemical agents like FM-200 or Novec 1230. These agents extinguish fires through a combination of cooling and chemical interference with the combustion process. They are effective at lower concentrations than inert gases and are generally considered safe for occupied spaces when used according to manufacturer guidelines.
Applications in Sensitive Equipment Areas
Gas suppression systems are ideal for protecting valuable and sensitive equipment from fire damage without the risk of water damage or conductive residue.
Safety Precautions and Considerations
When using gas suppression systems, it’s crucial to follow strict safety precautions, including proper ventilation after discharge and ensuring that occupants are evacuated before the system is activated, especially for inert gas systems.
Fire Extinguishers and Hose Reels, First Attack Capabilities
While automatic suppression systems are vital for controlling larger fires, fire extinguishers and hose reels provide a crucial first line of defense for tackling small, incipient fires.
Types of Fire Extinguishers and Their Appropriate Uses
As mentioned earlier, different types of fire extinguishers are designed for different classes of fires. It’s essential to have the right type of extinguisher available for the specific hazards in each area of the industrial building and to ensure that employees are trained on how to use them correctly.
Placement and Accessibility
Fire extinguishers should be strategically placed throughout the building, be easily accessible, and be clearly visible. Their location should be marked with appropriate signage.
Training on Effective Use
Simply having fire extinguishers available is not enough. Employees must receive proper training on how to select the correct extinguisher for the type of fire and how to operate it effectively.
Fire Hose Reels, Extended Reach for Initial Response
Fire hose reels provide a more substantial and continuous supply of water compared to fire extinguishers, allowing trained personnel to tackle larger incipient fires. They are typically located in cabinets and have a long hose that can reach a considerable distance.
System Selection and Integration, A Holistic Approach
Choosing the right fire suppression systems for your industrial building requires careful consideration of the specific hazards, the value of the assets being protected, and the potential impact of a fire on business continuity. Often, a combination of different suppression systems will be the most effective approach.
Factors to Consider
Key factors to consider when selecting a suppression system include..
- The type of materials present and the potential fire hazards.
- The size and layout of the building.
- The sensitivity of the equipment or materials being protected.
- The occupancy of the building.
- Relevant Australian Standards and building codes.
Integration with Fire Detection and Alarm Systems
As we’ve seen, fire detection and suppression systems work best when integrated. The fire detection system provides the early warning, while the suppression system automatically or manually intervenes to control or extinguish the fire.
Your Shield Against Industrial Firestorms
Fire suppression systems are an indispensable component of fire safety in Australian industrial buildings. They provide the means to actively combat fires, limiting damage, protecting lives, and ensuring business continuity. By understanding the different types of systems available, ensuring proper design, installation, and maintenance, and integrating them with fire detection and alarm systems, you can create a robust shield against the potential devastation of an industrial firestorm. Don’t wait until it’s too late – invest in the suppression systems that will help you contain and conquer any fire that may arise.
References:
- Australian Standard AS 2118 series: Fire sprinkler systems
- EPA regulations regarding PFAS-containing fire fighting foams
- SafeWork NSW – Working safely with PFAS containing aqueous film-forming firefighting foams – Technical guide
