Overview

Wet valve sprinkler systems are permanently charge with water and used to protect premises where temperatures are unlikely to fall below freezing point.  They may be installed vertically or in some cases, horizontally, and they are designed to actuate operate electric, and/or hydraulic alarms when there is a steady flow of water into the system that is equivalent to the discharge rate of one or more sprinklers.

The type of sprinkler nozzle, its discharge pattern and flow rate are all pre-determined by the hazard classification of the type of fire risk involved. When the fire system is initially being pressurised, water will flow into the system until the water supply and system pressure become equalised, and the torsion spring closes the clapper in the Alarm Check Valve and forms a seal.  This seal prevents any water flow through the alarm port to the alarm devices.

A typical Wet valve sprinkler system comprises of a control valve, sprinkler discharge heads and a dedicated water supply system.

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