Avoiding Structural Damage: The Key Role of Pressure Relief Dampers in Fire Suppression Systems

Pressure venting is an essential adjunct to many types of gaseous fire protection systems, but incorrectly designed venting can have serious consequences.

Solarfire Systems calculate the size of the damper required at the design phase of your project and will source and supply the most suitable pressure relief damper for the project.

Pressure Relief is required to protect the structural stability of the protected room or enclosure.

A pressure relief damper, also known as an overpressure damper, is an important component in fire suppression systems, particularly those that use gaseous extinguishing agents like FM-200, Novec 1230 (FK-5-1-12) or inert gases such as IG-55 Argonite or IG-541 Inergen.

Here's a detailed explanation:

Purpose and Function

  1. Pressure Management: When a gas-based fire suppression system is activated, it rapidly discharges the extinguishing agent into the protected room. In the case of synthic gases such as Novec 1230 or FM-200 this is under 10 seconds. This rapid discharge can create a significant increase in pressure within the enclosed space. If not properly managed, this overpressure can damage the room's structural integrity, windows, doors, and other fixtures.
  2. Pressure Relief: There are two types of pressure relief dampers, Dual flow, the air flows both out as well as in. And the Inert gas pressure relief damper. Pressure relief dampers are designed to automatically open when the pressure within the room exceeds a predetermined threshold. This allows the excess pressure to be safely vented out of the room, thus protecting the structural integrity of the space.
  3. Maintaining Room Integrity: While it allows excess pressure to escape, the damper also ensures that the room remains sufficiently sealed to contain the fire suppression agent for the required duration to effectively extinguish the fire.

Installtion and Considerations

  1. Location: The dampers are typically installed in the walls or ceilings of the protected room. The exact placement depends on the room's layout and the design of the fire suppression system.
  2. Size and Capacity: The damper must be appropriately sized to handle the expected volume of gas discharge. This requires careful calculation based on the type and quantity of the extinguishing agent used and the room's volume.
  3. Dual Flow: The "dual flow" aspect means that the damper can handle pressure differentials in both directions. This is important because, in some cases, the room might need to be vented in or out depending on the fire suppression agent.
  4. Compliance with Standards: Installation must comply with relevant safety and building codes, such as those outlined by the British Standards or other local regulations. These standards ensure that the damper will function effectively under fire conditions.
  5. Testing and Maintenance: Regular testing and maintenance are critical to ensure the damper's proper functionality. This includes checking the operational integrity of the damper, ensuring it opens at the correct pressure threshold, and verifying that it is not obstructed.


In summary, a dual flow pressure relief damper or overpressure damper is a critical safety component in gas fire suppression systems, designed to protect both the room's structural integrity and the occupants by safely managing pressure levels during the discharge of the extinguishing agent.

SolarFire Systems is National Security Inspectorate (NSI) Silver and BS EN ISO 9001/ BS EN ISO 14001/ accredited. We are also BAFE Accredited and members of the Fire Industry Association. All our approved gas extinguishing systems meet European and British standards as well as the exacting requirements of insurers. If you are considering having a fire extinguishing system fitted, get in touch. One of our experts will visit your property and undertake a thorough free assessment before designing a bespoke extinguishing system that gives you the most comprehensive protection possible.

Call us today to discuss your requirements on 01628 902107 or email us [email protected]

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