Preaction Systems
In a preaction system the sprinkler pipes are normally dry or filled with low-pressure air; water enters the pipes only when a fire detector alarms and the preaction valve opens. This prevents water from discharging on its own from a broken sprinkler or damaged pipe.
In the single interlock type the detector signal is enough; the double interlock type needs both a detector signal and the air pressure drop of an opened sprinkler. It is used in data centres, archives, museums, server and control rooms where accidental water discharge would cause severe damage.
Main Applications
- Data centres and server rooms
- Archives and libraries
- Museums and art storage
- Control and telecom rooms
- Sensitive storage in cold areas
Technical Data
| System type | Preaction sprinkler |
|---|---|
| Main element | Preaction valve |
| Interlock | Single or double interlock |
| Release | Fire detector + solenoid |
| Pipe content | Dry or low-pressure supervisory air |
| Alarm | Pressure switch and alarm gong |
| Size and connection | By model (please ask) |
| Approval | UL / FM / VdS certificate by model |
Material Options
| Part | Function |
|---|---|
| Preaction valve | Admits water to the pipes after detector confirmation |
| Solenoid | Releases the valve on the panel signal |
| Supervisory air | Monitors pipe tightness |
| Manual release | Provides manual triggering in an emergency |
| Alarm switches | Report low air and water flow |
Which material? A double interlock system gives the same freeze protection as a dry system while lowering the risk of accidental discharge; type selection and fire panel integration are done with the project team.
Advantages
Against Accidental Discharge
- No water from a broken sprinkler
Pipe Supervision
- Leaks monitored by air pressure
Early Warning
- Detector alarm comes before water
Freeze Protection
- Pipes can be kept dry
Construction and Design Features
- Preaction valve with solenoid release
- Supervisory air pressure trim
- Manual release and reset arrangement
- Alarm switches wired to the fire panel
Send the protected volume, interlock type and fire panel used; we will define the preaction station components together.
How to Choose?
- Assess damage riskChoose preaction where accidental discharge is critical.
- Set the interlock typeConsider double interlock for higher security.
- Plan panel integrationClarify detector and solenoid wiring.
- Select supervisory airPlan a compressor or nitrogen supply.
Complementary Products
Why ORFA?
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Details →Get a quote for your project
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