Deluge Systems

A Deluge and sprinkler system may look similar but they work very differently. 

A deluge system floods an entire area with water when a fire is detected, using open nozzles connected to a water supply via a deluge valve, which when opened covers the entire area simultaneously.

On the other hand, a sprinkler system has individual heads that activate independently from the heat of a fire, thus only the nozzles subjected to the heat of a fire will activate. That’s why deluge systems are used in particularly high-hazard areas where rapid fire spread could cause sprinklers to be ineffective due to the slower activation speed. 

Choosing the right deluge valve size depends on factors such as water supply, flow rate, and the activation system design.  Some deluge valves are electrically activated, others pneumatically activated.  Some valves are remotely resettable (i.e. the valve resets when you reset the detection control panel) whilst other valves may be only locally resettable (i.e. you perform the reset procedure mechanically, at the valve).  Our designers at Blazequel will guide you through choosing the correct deluge system for your hazard requirements.

Regular testing of deluge systems is essential to verify correct system operation.  A full wet test of the system is best (and is often required by the insurers as a witness test on completion of installation).  However, that’ s not always practical in an operational environment so sometimes we’ll just conduct a dry ‘trip test’ of the valve to prove the valve and signals operation without discharging water. 

For that to be possible, it is required to have an isolation valve downstream of the deluge valve – this creates a small ‘test chamber’ in the pipework into which the system can be discharged without flowing water out of the nozzles’ Additionally, fire detection systems can be independently tested without requiring a complete wet test of the deluge system. For further details on testing your deluge system, contact us. 

Deluge valves can be automatically triggered by fire detection systems or manually activated through a convenient push-button alarm point.  There may also be a manual activation function on the deluge valve trim as an emergency fail-safe feature.  After activation, the valve can be manually reset, locally or remotely, depending on the type. These features must be considered and designed correctly, to prevent the risk of accidental shut-off of the deluge zone in the event of a fire. 

Depending on the type of deluge valve installed, a system can be reset manually, locally, or remotely. Deluge valves lack automatic reset capabilities to prevent the risk of accidental resetting, which might happen if a fire damages the reset or detection line. However, remote manual reset is available in large environments or hazardous areas where direct manual reset is not preferred. 

Foam deluge systems use various expanding foams, which would be selected as appropriate for the hazard type. Foams can be discharged as high expansion (from specialist foam generators such as in aircraft hangers), medium expansion, or low expansion.  In applications where there is a significant fire load of Class A materials (flammable solids such as waste, wood, paper etc.), a wetting agent may be used to break the surface tension of the discharged water. Different types of foam system fight fires differently.

The cost of a deluge system in the UK can vary significantly depending on factors such as the system’s size, installation complexity, choice of components, and specific site requirements. 

Generally, a basic deluge system starts from a few thousand pounds for smaller installations, while larger and more complex systems for industrial or commercial applications cost tens of thousands of pounds or more. Contact us to get an accurate quote tailored to your needs.