Dry Valve Sprinkler Systems

Dry valve sprinkler systems are permanently charged with air and used to protect unheated premises such as warehouses, parking garages, attic spaces and other areas exposed to freezing temperatures. 

When the system is set is charged with air, the minimum air pressure includes a safety factor to prevent potential “Towns Main” water pressure fluctuations from forcing the Dry valve clack open to allow water into the system pipework 

An accidental loss of air pressure will initiate a low air pressure alarm to alert the building’s fire safety officer to the situation. A rapid loss of air pressure through an operated automatic sprinkler in response to heat from a fire will allow the water pressure within the Dry valve to overcome the differential holding the clapper assembly closed. This allows the clapper assembly to open and allow water to be discharged into the pipework system and be discharged through any open sprinklers.

When there is a steady flow of water into the system that is equivalent to the discharge rate of one or more sprinklers, electric, and/or hydraulic alarms will be initiated.

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. 

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