DUX
Duflow Pressure Vent for Chemical Gas
Product details
- Two-way pressure relief vent for both positive and negative pressure venting.
- Applicable with gas fire suppression systems using chemical gases.
- Negative pressure relief: Operates at 85 Pascals and fully open at 100 Pascals.
- Positive pressure relief: Operates at 100 Pascals and fully open at 120 Pascals.
- Available in 4 standard sizes.
- Can be adapted for ceiling mounted applications.
- Constructed from Steel Zintec and powder coated with RAL 9003 white.
- 5-year warranty.
- Available off the shelf for next day delivery.
Kit: The kit includes a wall liner, wall liner extension and fitting kit. The standard kit can be installed into walls up to 380 mm. For thicker walls, additional wall liner extensions are required.
Note: The standard DMX units may be subject to rust if exposed to corrosive environments such as costal installations. For non-corrosive units, please ask about our stainless steel range.
DUX | Two-way pressure vent
The DUX is the world’s first two-way pressure relief vent specifically designed for halocarbon gaseous agents like FM-200 and Novec (patent pending). It delivers unmatched performance in synthetic gas suppression pressure relief systems.
Unlike traditional vents, the DUX features AFP’s advanced aerofoil-style blades, which are top-weighted and pivoted for optimal efficiency and fast response. Its unique two-pivot design allows adjacent blades to interlock, ensuring superior fire protection with minimal leakage and highly effective pressure relief.
Tested using the 2008 BRE live gas discharge tests, the DUX is the only vent on the market with a certified Free Vent Area (FVA) to BRE standards.
For additional performance validation, the DUX can be tested on AFP’s Blast Simulator under real-world conditions using FM-200 and Novec gas suppression systems.
For placement in external walls, the Expander Box Weather Louvre is required.
Certifications & testing
- 4 Hour Fire Resistance rated by Chiltern to BS EN 1363-1.
- Live discharge test 122084, certified by BRE.
Types of gases
The DUX is a two-way pressure relief vent designed to manage both positive and negative pressure during chemical gas fire suppression discharges. Specifically engineered for use with halocarbon gases, it provides reliable protection for critical spaces like data centers, laboratories, and control rooms, where fast suppression and minimal residue are essential.
Halocarbon gaseous agents compatible with the DUX include:
- FK-5-1-12 (Fluoroketone - C₆F₁₂O). Novec is a popular brand for this gas.
- HFC-227 (Heptafluoropropane - C₃HF₇). FM200 is a popular brand for this gas.
Placement
According to FIA and ISO, the guidance for the placement of pressure relief vents is that they are mounted directly to the atmosphere, not to be obstructed in any way and that they are not placed near a discharge nozzle.
It is often recommended to install pressure relief vents high in the room, because chemical gases are heavier than air and tend to sink. A vent placed lower down could potentially cause leaks, but the effects of this have not been fully studied or tested.
Benefits of certification
Rigorous testing and certification are important to ensuring that pressure relief vents meet the highest safety and performance standards. In real-world applications, certified vents like the DUX provide reliable performance under extreme conditions, including gas discharges, pressure fluctuations, and fire events—minimizing risks to personnel and infrastructure.
Certification to industry standards, such as the BRE Live Gas Discharge Test, confirms that the DUX is fully compatible with gas suppression system calculations. This ensures accurate pressure management, maintaining safe operation and preventing dangers evolving from a high positive or negative pressure environment during a live gas release.
Fire resistance testing verifies that the DUX acts as an effective fire barrier when installed in a block wall, offering essential protection in high-risk environments. Additionally, extensive blast resistance testing demonstrates its ability to withstand extreme pressure changes, preventing structural damage and preserving the integrity of protected spaces. Through comprehensive certification, the DUX guarantees consistent, reliable performance when it matters most.
Integrity Testing Calibration
AFP’s range of pressure relief vents, including the DUX, do not require calibration from an integrity test, as they are fully certified to the 2008 BRE Live Gas Discharge Test.
Get in touch
Get in touch for a quote, more information, assistance with correct sizing, or bespoke solutions tailored to your needs.
Product operation video
Watch the video below to have a closer look at what makes the DUX unique, and how it effectively manages both positive and negative pressure during a gas discharge.
Unit selection
The DUX pressure relief vents are offered in a number of standard sizes for installation in both internal and external walls.
| Product Code | DUX300 | DUX500 | DUX700 | DUX1000 |
| Neg Free Vent Area | 0.077m2 | 0.212m2 | 0.416m2 | 0.85m2 |
| Pos Free Vent Area | 0.047m2 | 0.128m2 | 0.308m2 | 0.556m2 |
| Overall WxHxD | 440x440x120mm | 640x640x120mm | 820x820x120mm | 1120x1120x120mm |
| Hole cut out WxH | 365x380m | 560x580mm | 760x750mm | 1060x1050mm |
| Weight | 15kg | 25kg | 33.5kg | 54kg |
Add-ons
EXP
The EXP offers superior wind and weather protection for external walls, without restricting the internal vents Free Vent Area (FVA).
Grilles
The AFP product range offers several security grilles to mount on vents in outside walls for different levels of protection.
Z-Frame
Powder coated steel stub duct for mounting the DUX two-way pressure vent into thin walls, doors, and cladding of less than 100 mm thick.
Wall liner
A wall liner is an extension for internal wall depths that exceed 15" thickness. With extra wall liners, minimal leakage and FVA will still be applicable.
Downloads
Access detailed technical information on the DUX duflow pressure relief vent, including data sheets, installation guides, and technical drawings, by downloading the resources below.
Get in touch
Get in touch for a quote, more information, assistance with correct sizing, or bespoke solutions tailored to your needs.
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