pre_action_singleDepending on the system’s intentions and coverage helps decide whether single or double interlock system should be installed. Pre-Action interlock functions in the same manner as a dry, wet, and deluge pipe systems, which is why it’s considered as a hybrid system. Only one event occurs before water is released by the single interlock, while in the double interlock system, two events occur. Both systems first event is fire detection and the double interlock’s second event is the operation of the automatic sprinkler. A pre-action valve operates so that the dry system converts into a wet system because both interlock systems are customized for information sensitive environments, like museums, data centers, etc.