SHX-OS
Offshore Pressure Relief Vent
Product details
- Largest verified Free Vent Area (FVA) on the market.
- Single direction venting for positive pressure.
- Pressure relief vent for inert gas fire suppression systems.
- Operates at 80 Pascals and fully open at 95 Pascals.
- 10 year guarantee.
- All 316L stainless steel construction.
- Adjustable opening pressure (Factory set) for offshore storm levels.
- Lifetime casing corrosion guarantee.
- Made to order.
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: For external walls the HBP-OS offshore high energy blast panel is required.
SHX-OS | Offshore Pressure Relief Vent
The SHX-OS is AFP’s dedicated pressure relief solution for offshore environments, engineered to combine high-performance venting with extreme durability in harsh conditions. Designed specifically for offshore platforms, it plays a critical role in protecting internal spaces from overpressure during gas discharges or arc fault events.
Constructed entirely from powder-coated 316L stainless steel, the SHX-OS is purpose-built for the offshore sector, offering a lifetime casing corrosion guarantee. It works seamlessly with AFP’s HBP OS external blast panels, forming a complete pressure relief system that maintains internal room integrity without compromising safety during live events.
With adjustable opening pressures, the SHX-OS can be tuned to accommodate high offshore wind loads, ensuring it remains closed under extreme weather conditions while still activating reliably in pressure discharge scenarios.
All units are fitted with a 'pull handle' so that opening force can be checked on site against factory calibrated win pressure settings.
Tailored to offshore infrastructure
The SHX-OS is a pressure relief vent, designed with ISO flange fixing points, allowing it to be easily integrated into a wide range of offshore structures. Its self-closing design ensures reliable re-sealing after a pressure event. The modular sizing options make it suitable for both new installations and retrofits.
When internal safety, fire resistance, and offshore corrosion protection are non-negotiable, the SHX-OS delivers dependable performance backed by live testing and real-world use.
Get in touch
Get in touch for a quote, more information, assistance with correct sizing, or bespoke solutions tailored to your needs.
Certifications & testing
The SHX OS offshore pressure relief vent has the following certifications. Click on a link to download the certificate.
- Live discharge test 122084, by BRE.
- AFP Blast and Explosion tested with AFP's blast simulator.
- 4 Hour Fire Rated, by Exova to BS EN 1363 - 1 I BS EN 1364-1 and ULSSS & ASTME 119-08a.
Evolving certification
Current units have been certified by DNV-GL on a project-by-project basis. We are now working to expand this certification to cover the entire SHX-OS product range, so that all future units will meet the same standard by default.
Proven Under Realistic Conditions
What sets the SHX-OS apart is its testing at the AFP Blast Simulator, a purpose-built facility that replicates the conditions of live discharges from inert gas suppression systems and GIS electrical units. Unlike static airflow tests, this simulator applies real-time pressure waves, capturing detailed data on how the vent performs in high-energy events. This testing proves not just compliance, but real-world reliability under the types of stress encountered on offshore platforms.
Benefits of certification
For offshore applications, certification is more than a formality—it’s a critical safeguard. The SHX-OS is tested and certified to meet the highest standards for safety and performance under extreme conditions. Whether facing a sudden gas discharge, an arc fault event, or a fire, a certified vent like the SHX-OS ensures that pressure is safely released, protecting both people and infrastructure.
Certified to the BRE Live Discharge Test (Report No. 122084), the SHX-OS is fully compatible with industry-standard gas calculation software, allowing engineers to model inert gas suppression pressure relief performance accurately. This precision helps prevent dangerous over-pressurisation during a live discharge, ensuring the vent opens exactly when needed and performs without delay or obstruction.
Fire testing confirms that the SHX-OS also acts as a reliable fire barrier when installed in a wall, providing up to four hours of rated protection in offshore or high-risk environments.
No integrity test calibration needed
Thanks to its full BRE Live Discharge Test certification, the SHX-OS does not require separate calibration during room integrity testing. This simplifies commissioning and ensures reliable, consistent performance from the moment the unit is installed.
Unit selection
The SHX-OS offshore pressure relief vent is made to order and can be delivered in the following sizes:
| Product Code | Free Vent Area | Flange Dimension (WxH) | Duct Size (WxH) |
|---|---|---|---|
| SHX OS 1000 | 0.870m2 | 1130x1130mm | 1050x1050mm |
| SHX OS 900 | 0.710m2 | 1030x1030mm | 950x950mm |
| SHX OS 800 | 0.564m2 | 930x930mm | 850x850mm |
| SHX OS 700 | 0.436m2 | 830x830mm | 750x750mm |
| SHX OS 600 | 0.324m2 | 730x730mm | 650x650mm |
| SHX OS 500 | 0.228m2 | 630x630mm | 550x550mm |
| SHX OS 400 | 0.149m2 | 530x530mm | 450x450mm |
| SHX OS 300 | 0.087m2 | 430x430mm | 350x350mm |
Add-ons
HBP-OS
The HBP OS is a multifunctional external blast panel for offshore platforms. It includes a full perimeter double seal for protection against the elements.
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 SHX-UN 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 SHX OS, including data sheets, installation guides, and technical drawings, by downloading the resources below.
- Data sheet
- Installation guide (available upon request)
- O&M manual (available upon request)
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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