Pre-action Sprinkler Systems

These systems are specifically designed for the protection of high value “Business Critical” areas where sensitive electrical equipment or goods are stored to provide prior warning of system discharge or prevent system discharge caused by accidental damage to a sprinkler or system pipework.

A Pre-action sprinkler system comprises a standard Deluge valve sprinkler system and an independent system of heat or smoke detectors installed in the same areas as the sprinklers.

The Deluge valve is a diaphragm style valve that depends upon air in the diaphragm chamber to hold the diaphragm closed against the water supply. Any accidental damage to a sprinkler or a detector head in a “non-fire” situation will NOT bring the control valve into action but will cause both visual and audible alarms to be raised to alert the building’s fire safety officer to the situation.

In the event of a fire, when two or more detector heads operate, they send a signal to the main fire control panel. On receipt of this signal, the fire control panel operates the solenoid release valve, releasing the pressure off the diaphragm unit to open the Deluge valve and discharge water into the system in readiness for a sprinkler head to open when it reaches its designated operating temperature.

This process provides the building’s fire safety officer with prior warning of the impending event so that the Company’s established fire control plan can be immediately initiated to minimise the impact of the fire threat.

The size of the Deluge valve, its flow rate, the system water supply pressure and type of detection system are all determined by the size and type of fire risk involved.

Sprinkler Discharge Heads
Water supply systems