FAST KNOCKDOWN AND COOLING PROTECTION FOR HEAVY EQUIPMENT FIRES
What is a Dual Agent Fire Suppression System?
A dual agent fire suppression system is an onboard fire protection system that uses both dry chemical and liquid agent to suppress fires on heavy equipment. The dry chemical agent provides fast flame knockdown and broad total-flooding coverage, while the liquid agent cools hot surfaces, penetrates debris, suppresses pooled fuel fires, and helps reduce the chance of reignition.
Dual agent systems are often recommended for large or high-risk machines with complex fire hazards involving fuel, hydraulic fluid, electrical components, combustible debris, and high operating temperatures.
Why Use Two Fire Suppression Agents?
Heavy equipment fires are complex. One part of the machine may need fast flame knockdown, while another may need cooling to prevent the fire from reigniting.
Dry chemical agent is effective for fast knockdown and total-flooding coverage, especially in enclosed or semi-enclosed areas. Liquid agent is effective for cooling hot surfaces, penetrating debris, suppressing pooled fuel fires, and reducing reignition risk.
By combining both agents, an AFEX dual agent system provides a more complete fire suppression approach for machines where one agent alone may not address the full risk.
When is a Dual Agent System a Good Fit?
Dual agent systems are a strong fit for machines with multiple fire hazards in the same protected areas. They are often used when equipment has high heat, large hydraulic systems, fuel exposure, electrical components, combustible debris, and surfaces that may remain hot after the initial fire is knocked down.
Dual agent fire suppression may be a good choice for:
- Hydraulic shovels
- Excavators
- Large wheel loaders
- Haul trucks
- Drills
- Frac pumps
- Forestry machines
- Waste handling equipment
- Steel and slag equipment
- Other large or high-risk mobile equipment
For some equipment, dual agent protection may also be required by applicable standards. NFPA 122 requires dual agent fire suppression for diesel-powered equipment with more than 150 gallons of hydraulic fluid.
Dual Agent System Features
AFEX dual agent fire suppression systems are designed for heavy-duty mobile equipment operating in demanding environments.
Key features include:
- Fast fire knockdown from dry chemical agent
- Cooling of hot surfaces from liquid agent
- Total-flooding coverage, especially in well-enclosed areas
- Helps reduce the chance of fire reignition
- Penetrates debris and suppresses pooled fuel fires
- Protection for Class A, B, and C fire risks
- Manual and automatic system discharge
- Small system footprint
- More economical than liquid chemical systems alone in some applications
- Suitable for temperatures as low as -40°F / -40°C
- Third-party tested and approved by FM 5970 HDME, Activfire AS 5062, and CE
THE CASE FOR DUAL AGENT FIRE SUPPRESSION SYSTEMS
Why One Agent Isn’t Always Enough
Fire hazards on heavy-duty equipment are rarely simple. A single machine may have diesel fuel, hydraulic fluid, grease, electrical components, combustible debris, and high-temperature surfaces all located near each other.
Some of these risks call for fast knockdown. Others require cooling and reignition control. That is why dual agent systems are often used on larger, more complex, or higher-risk equipment.
Dual Agent Vehicle Fire Suppression System in Action
Watch how an AFEX dual agent fire suppression system uses both dry chemical and liquid agent to provide fast flame knockdown, total-flooding coverage, surface cooling, and protection against reignition.
System Accessories
AFEX dual agent fire suppression systems can be configured with accessories that support operator awareness, system monitoring, machine shutdown, and long-term serviceability.
Available accessories include:
- Stainless steel tubing distribution to reduce the need for costly hose replacements
- Telematic integration through the AFEX Control Unit monitor panel
- Engine shutdown package to help limit intensified fire damage from continued fuel or hydraulic flow
- Fire sleeves for wires and hoses to provide additional heat and flame resistance
- Horn and strobe for secondary audio and visual notification of an alarm condition
- Pushbutton for an electronically monitored means of manual system activation
These accessories help tailor the system to the machine, the environment, and the operational needs of the site.
Control Unit for Heavy Equipment Fire Suppression
Dual agent systems can be paired with the AFEX Control Unit for advanced fire detection and system monitoring.
The Control Unit is a highly configurable detection panel with multiple inputs and outputs, allowing fire suppression systems to be designed around the equipment, environment, and site requirements. It supports system monitoring, actuation, accessory integration, and telematics.
