15LB Amerex 331 - CO2 Fire Extinguisher - OEM

The Amerex 331 is a high-performance, 15 lb Carbon Dioxide (CO2) fire extinguisher designed for environments where collateral damage from extinguishing agents is as great a threat as the fire itself. In modern laboratories, telecommunication hubs, and electrical rooms, the corrosive dust of a standard dry chemical extinguisher can permanently bridge circuits and destroy sensitive sensors. The Amerex 331 solves this by utilizing pure, industrial-grade CO2 — a clean, non-contaminating agent that vanishes instantly after discharge, leaving zero residue.

Rated 10-B:C, the Amerex 331 is specifically engineered to tackle flammable liquid fires and energized electrical equipment. As the mid-sized CO2 unit in the Amerex lineup, it offers significantly more discharge capacity than smaller models while remaining light enough for manual deployment. Built with a rust-free aluminum cylinder and a heavy-duty all-metal valve assembly, the 331 is an indispensable safety asset for those requiring non-contaminating fire suppression for high-value infrastructure.

The Science of Suppression: Sublimation and Oxygen Displacement

1. Atmospheric Oxygen Displacement

Combustion requires a minimum of 16% oxygen to continue. When the Amerex 331 is activated, it floods the hazard zone with a concentrated cloud of CO2, rapidly dropping the local oxygen level below the threshold of combustion. Because CO2 is 1.5 times heavier than air, it sinks into electrical cabinets and under floor voids, providing deep coverage in enclosed spaces.

2. The Snow and Sublimation

As the liquid CO2 exits the specialized discharge horn, it undergoes a rapid pressure drop, turning into a mixture of gas and dry ice snow at approximately -110°F. This snow quickly sublimates — converting directly from solid to gas — absorbing massive amounts of thermal energy. While the primary suppression method is oxygen exclusion, this extreme cold provides a secondary cooling effect that helps prevent thermal runaway in overheated hardware.

3. Non-Conductive Dielectric Strength (Class C)

Carbon dioxide is naturally non-conductive and non-corrosive. This allows an operator to safely engage fires in live 480V panels or medical imaging equipment without risk of electrical flashover — a core requirement for telecommunications and high-voltage electrical environments.

Why the Amerex 331 is the IT and Lab Manager's Choice

• Zero-Residue Logistics: Following a discharge, there is no powder to vacuum and no corrosive film to remediate — critical for laboratory environments where post-fire cleanup could contaminate ongoing experiments or damage irreplaceable equipment.
• Capacity-to-Weight Ratio: The 15 lb agent capacity provides approximately 15 seconds of discharge time, giving the operator meaningful time to ensure full suppression — significantly more than smaller CO2 units.
• Rust-Free Aluminum Construction: The aluminum cylinder body is naturally rust-resistant, maintaining structural integrity and professional appearance even in humid mechanical rooms and laboratories.

The Amerex 331 is the primary choice for low-contamination hazard zones where clean agent suppression is mandatory:

• Hospitals and Medical Rooms: Protecting surgical lasers and medical imaging equipment where chemical residue is strictly prohibited.
• Laboratories and Research Facilities: Protecting delicate glass apparatus and precision instrumentation from the abrasive cloud of dry chemical agents.
• Electrical Control Rooms: Used near high-voltage panels and switchgear for clean, zero-residue suppression.
• Telecommunications Hubs: Essential for protecting switching gear and network infrastructure where continuity of service is the primary concern.
• Clean Manufacturing: Safeguarding automated control systems and precision equipment from chemical contamination.

To maintain NFPA 10 compliance and ensure insurance eligibility, the 331 must follow a strict maintenance protocol:

• Monthly Visual Inspection: Verify the safety seal is intact and the discharge horn is clear of obstructions. Confirm inspection tags are current.
• Annual Professional Service: A technician must verify the unit's weight. CO2 units are checked by gross weight — there is no pressure gauge, so weight is the only reliable indicator of a full charge.
• 5-Year Hydrostatic Test: Mandatory every five years due to the high storage pressure of CO2 vessels, to ensure structural integrity.
• Confined Space Warning: Because CO2 displaces oxygen, the area must be ventilated immediately after any discharge, and personnel must not re-enter until oxygen levels are confirmed safe.

Where can I find service for CO2 units?

Visit a specialized fire equipment store or an authorized Amerex dealer for proper weight verification, hydrostatic testing, and recharge. CO2 units require specialized pressurization equipment and cannot be serviced with standard dry chemical tooling.

Is this a Class ABC extinguisher?

No. The 331 is rated 10-B:C — it is designed for Class B flammable liquid fires and Class C electrical fires. It is not a Class A extinguisher and will not prevent re-ignition in deep-seated wood or paper fires. For Class A applications, specify a water or ABC dry chemical unit.

How do I operate this unit safely?

Use the PASS method: Pull the pin, Aim the discharge horn at the base of the fire, Squeeze the handle, and Sweep from side to side. Always grip the insulated handle on the discharge horn — never the horn itself, as it reaches approximately -110°F during discharge and will cause frostbite on contact.