IFV
Instant Flow Vent
Product details
- Instant flow blast relief in under 10ms.
- Designed for air insulated switchgear and open-air arc flash events.
- Applicable for rapid sub-30ms pressure spikes.
- Can be fire rated with an intumescent grille.
- Optional heavy-duty security grille (SR2 or SR3 on request).
- Internal powder coated RAL 9003. External powder coated RAL 9006.
- 5 year corrosion guarantee.
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: These units may be subject to rust if exposed to corrosive environments such as coastal environments. For non-corrosive units, construction in 316 stainless steel is available on request.
Get in touch
Get in touch for a quote, more information, assistance with correct sizing, or bespoke solutions tailored to your needs.
IFV Instant Flow Vent
The AFP Instant Flow Vent (IFV) has been developed to address one of the most critical challenges in electrical safety: ultra-fast blast venting. It is specifically designed for air insulated switchgear (AIS) and open-air arc flash events, where traditional ventilation products cannot keep pace as peak pressure suppression needs to be in the sub 60ms range.
The difference between gas insulated switchgear and air insulated switchgear
In gas insulated switchgear (GIS), pressure builds more slowly. A rupture disk with a small opening (typically around 125 mm) restricts the gas flow. This delay means that conventional blast vents, which take around 60ms to open, usually provide sufficient protection.
In air insulated switchgear (AIS), the situation is very different. With no rupture disk to limit expansion, gases move freely and pressure inside the room can climb in under 30ms.
Some systems use blow-out doors as a safety measure, but these are not effective. They only open after pressure has already started to build, and when they do open, their large surface area allows a large volume of air flow, resulting in a sudden rush of expanding gases. Instead of reducing the spike, this can make the pressure inside the room rise even faster.
The solution for air insulated switchgear
The AFP IFV is engineered to deliver instant blast relief in under 10ms. By opening before pressure can peak, it prevents dangerous surges that would otherwise exceed safe design limits. This makes the IFV the only reliable option for AIS and open-air arc flash conditions where sub-30ms spikes are common.
The design consists of a venting unit that opens immediately under blast conditions, providing a clear and unobstructed path for expanding gases. Its core vent blades are lightweight but robust, ensuring high speed regulation of airflow. The frame is powder coated for corrosion protection and durability during repeated events.
For added protection, the IFV can be fitted with a heavy-duty security grille (available to SR2 or SR3 standards on request) and a mesh wall liner. These are optional extras, allowing the vent to be adapted to the specific security or installation requirements of each site.
Tested and verified performance
The IFV has been extensively tested in the AFP Blast Simulator, where its opening speed and stability have been verified under live blast conditions. Using a 150 mm air cannon charged to 5 bar, AFP measures vent blade positions in 5ms increments, ensuring precise data on the Free Vent Area (FVA) over time.
This data is now integrated into AFP’s calculation sheet, which models arc flash events more accurately by comparing pressure rise against vent opening rates. The tool applies to GIS, AIS, and open-air arc faults, giving engineers reliable insight into system performance and the precise regulation of airflow.
With the addition of a smaller blast chamber, AFP can now also test one-bar overpressure events, simulating external explosions such as those found in chemical plants.
Certifications & testing
- Blast and explosion tested with the AFP blast simulator.
More certifications and test results are available upon request. Please get in touch for more information.
Why testing matters
The IFV has been rigorously tested in AFP’s blast simulator to validate its ability to provide ultra-fast relief during extreme arc flash events. Unlike conventional vents, which may take up to 60ms to fully open, the IFV delivers blast relief in under 10ms, directly addressing rapid sub-30ms pressure spikes common in air insulated switchgear.
Testing confirmed not only the speed of response, but also the vent’s stability and durability under repeated high-pressure events, ensuring reliable protection for critical electrical infrastructure.
Unit selection
Please find below the standard sizes of the IFV Instant Flow Vent, or get in touch for custom sizes.
| Product Code | IFV300 | IFV500 | IFV700 | IFV1000 |
| 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 |
Add-ons
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 SHX-UN, 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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