Pre-action fire sprinkler systems employ the basic concept of a dry pipe system in that water is not normally contained within the pipes. First, the detection system must identify a developing fire and then open the pre-action valve. These systems require that both a “preceding” fire detection event, typically the activation of a heat or smoke detector, and an automatic sprinkler operation take place prior to the “action” of water introduction into the system's piping. react faster than dry system, and contain no water in pipes.

Pre-action sprinkler systems are specialized for use in locations where accidental activation is undesired. This may be museums, special technology companies, data centers with lots of computers etc.