SHX-UN SS
Universal Stainless Steel Pressure Relief Vent
Product details
- Largest verified Free Vent Area (FVA) on the market.
- Single direction venting for positive pressure relief.
- Applicable with gas fire suppression systems using inert gases.
- Operates at 80 Pascals and fully open at 95 Pascals.
- Available in 4 standard sizes.
- Can be adapted for ceiling mounted applications
- Constructed from 316L Stainless Steel
- Lifetime Corrosion Guarantee
- Available off the shelf on 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 200 mm. For thicker walls, additional wall liner extensions are required.
Note: For external walls the DWP SS Dynamic Weather Panel is required.
SHX-UN SS | Universal Stainless Steel Pressure Relief Vent
The SHX-UN SS is AFP’s premium universal pressure vent, engineered to offer industry-leading performance for inert gas suppression systems and blast protection. Made entirely from 316L stainless steel, the SHX-UN SS delivers lifetime corrosion resistance and exceptional durability, making it the trusted choice for mission-critical applications in data centres, electrical switchgear rooms, and transformer enclosures.
Unmatched venting performance
What sets the SHX-UN SS apart is its third-generation design, which has evolved through years of in-house engineering and live testing. It features a top-weighted blade system and curved interlocking edges, designed to open with maximum efficiency during gas suppression events. As a result, the SHX-UN SS achieves 100% of its verified Free Vent Area (FVA) at extremely low pressures, fully opening at just 95 Pascals.
It is currently the only pressure vent on the market with a third-party verified FVA, certified under BRE Live Discharge Test 122084, and proven to outperform in both inert gas release and high-energy blast events.
Versatile installation options
The SHX-UN SS can be mounted in both wall and ceiling configurations, including the ceiling-specific CEI model. It fits standard wall constructions (from thin panels to up to 200 mm thick walls) without the need for additional parts. A full fitting kit, wall liner, and installation instructions are included with each unit.
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Get in touch for a quote, more information, assistance with correct sizing, or bespoke solutions tailored to your needs.
Certification & Testing
- Live discharge test 122084, by BRE live gas discharge tests.
- AFP Blast and Explosion tested with AFP's blast simulator.
- 4 Hour Fire Rated by Exova to BS EN 1363-1 and BS EN 1364-1.
Proven in real-world scenarios
Unlike traditional HVAC vent designs, which are tested under static airflow conditions, the SHX-UN SS has undergone live gas and explosion discharge testing with full data logging. This ensures it operates reliably under rapid pressure increases typical in real emergencies such as gas suppression events. The SHX-UN SS has also been tested for cascade venting and blast pressures exceeding 60 kPa, making it suitable for more demanding environments.
Benefits of certification
Through being certified to the BRE Live Discharge Test standard, the SHX-UN Stainless Steel universal pressure relief vent can be used with the industry's gas calculation software to guarantee performance in the event of a live gas discharge. This prevents dangerous over-pressurisation of buildings caused by incorrect vent design or certification. The vents also provide an effective fire barrier to recognised fire testing standards when fitted into a fire wall.
The SHX-UN range is now rated for blasts in excess of 60 kpa. They can also be motorised for ventilation and other specialist venting combinations, whilst maintaining their ability to dissipate gas over-pressurisation without any loss to their standard pressure venting efficiency.
Extensive testing history ensures that the right vent can always be provided for any requirement.
Integrity testing calibration
The AFP range of pressure vents does not require calibration from an integrity test as they are fully certified to the BRE Live Discharge test of 2008.
Unit selection
The SHX-UN Stainless Steel pressure relief vents are offered in a number of standard sizes for installation in both internal and external walls.
| Product Code | SHX-UN SS300 | SHX-UN SS500 | SHX-UN SS700 | SHX-UN SS1000 |
| Free Vent Area | 0.077m2 | 0.212m2 | 0.416m2 | 0.85m2 |
| Overall WxHxD | 420x420x120mm | 620x620x120mm | 820x820x120mm | 1120x1120x120mm |
| Hole cut out WxH | 360x350mm | 560x550mm | 760x750mm | 1060x1050mm |
| Leakage (3% of FVA) | 0.0023m2 | 0.0063m2 | 0.0121m2 | 0.038m2 |
| Wall Mounted Weight | 12kg | 19kg | 34kg | 53kg |
| Ceiling Mounted Weight | 11.5kg | 17.5kg | 30.5kg | 44kg |
Add-ons
DWP-SS
The DWP-SS offers superior wind and weather protection for external walls, without restricting the internal vents Free Vent Area (FVA).
HE-BP SS
The HE-BP High Energy Blast Panel is for weather protection when an SHX-UN SS is installed on an external wall in a substation or switch gear within 10km of the coast.
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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