Pre-Action Valve
A sprinkler system employing sprinklers that are attached to a piping system that contains air that might or might not be under pressure, with a supplemental detection system installed in the same areas of the sprinkler heads them selves.
Deluge Valve
A sprinkler system employing open sprinklers that are attached to a piping system that is connected to a water supply through a valve that is opened by the operation of a detection system installed in the same areas as the sprinklers. When this valve opens, water flows into the piping system and discharges from ALL of the sprinklers attached thereto.
Dry Valve
A sprinkler system employing automatic sprinklers that are attached to a piping system containing air or nitrogen under pressure, the release of which permits the water pressure to open a valve known as a dry pipe valve, and the ater then flows into the piping system and out the opened sprinkler heads.
Wet Valve
A sprinkler system employing automatic sprinklers attached to a piping system containing water and connected to a water supply so that water discharges immediately from sprinklers opened by heat from a fire.
