Pre-Action & Deluge Systems
WSD delivers the electrical side of pre-action and deluge fire suppression systems for data centres, electrical switch rooms, archives, museums and other environments where accidental water discharge would cause more damage than the fire it was preventing. Detection design, control panels, cause-and-effect programming, suppression release integration and ongoing maintenance, working alongside the sprinkler contractor handling the mechanical pipework.
If you’re an M&E consultant, main contractor, sprinkler company or FM provider looking for a specialist electrical contractor to handle the detection and control side of a pre-action or deluge project, this page is for you.
Both pre-action and deluge are sprinkler systems designed for environments where standard wet-pipe sprinklers carry too much risk of accidental discharge.
- Pre-action systems – the sprinkler pipework is dry under normal conditions. Water only enters the pipework when a separate detection system (typically fire alarm or aspirating smoke detection) registers a fire condition. A second event (heat-triggered sprinkler head activation, in a double-interlock configuration) then releases the water through the activated sprinkler. The result: a sprinkler system that won’t dump water on a server hall because a pipe joint failed
- Deluge systems – all sprinkler heads in the protected zone are open, and water is held back by a deluge valve. When detection identifies a fire, the deluge valve opens and all sprinklers in the zone discharge simultaneously. Used in high-hazard environments where rapid, total water coverage is the right response
Both system types depend completely on the detection and control side being designed, installed and integrated correctly. That’s where WSD comes in.
What WSD delivers on a pre-action or deluge project
We deliver the complete electrical scope:
- Detection design and installation – selecting and installing the right detection technology for the environment (addressable fire alarm, point smoke, beam smoke, aspirating smoke detection (VESDA), heat detectors, linear heat detection cable, flame detectors where appropriate)
- Control panels – selection, installation, programming, integration with the deluge valve or pre-action panel
- Cause-and-effect programming – matrix design and configuration so the right detection event triggers the right suppression response with the right interlocks
- Suppression release integration – electrical interface with the deluge valve, pre-action solenoid or gas suppression release
- Interlocks – door interlocks, audible and visual warning, plant shutdown, HVAC isolation, BMS reporting
- Commissioning – end-to-end functional testing across the detection, control and release matrix
- Maintenance – planned servicing of the electrical and detection side alongside the wider fire safety maintenance contract
The sprinkler company handles the mechanical pipework, valves and sprinkler heads. We handle the electrical, detection and control. The two scopes meet at the deluge valve or pre-action panel interface, which we co-ordinate jointly during commissioning.
Recent Pre-Action & Deluge Systems installs & upgrades.
A small selection of jobs we have delivered or maintain in this area.
Sherborne MRF Sprinkler Upgrade
Replacement of zone-check systems and upgraded pump controls across a 12,000 m² material recovery facility, completed in two phased weekend shutdowns.
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What’s the difference between pre-action and deluge sprinkler systems?
Pre-action systems hold the sprinkler pipework dry and only admit water when a separate detection system identifies a fire. Sprinkler heads then activate normally when heat reaches them, in a double-interlock pre-action configuration. Deluge systems have open sprinkler heads throughout the zone, with water held back by a deluge valve. When detection identifies a fire, the deluge valve opens and all sprinklers in the zone discharge simultaneously.
Do you install the actual sprinkler pipework?
No. The mechanical sprinkler pipework, valves and sprinkler heads are typically installed by a specialist sprinkler company. WSD handles the electrical, detection and control side. The two scopes meet at the deluge valve or pre-action panel interface, which we co-ordinate during commissioning.
Which manufacturers do you work on for pre-action and deluge?
Tyco, Viking, Reliable, Victaulic, and other LPCB and FM approved equipment.
Can you pair pre-action with VESDA?
Yes. VESDA aspirating smoke detection is one of the most common detection methods paired with pre-action sprinkler systems in data centres and similar high-value environments, often in a double-interlock configuration.
Do you cover the whole UK?
Yes, we deliver maintenance contracts and projects nationally from our Bromsgrove HQ. Most of mainland Britain is within a routine response window for reactive maintenance work.
Sites further from the Midlands may have slightly longer response windows for reactive call-outs; we can provide a map of typical response times by area during the initial survey if it’s relevant to your site.