Abstract: An activation unit for a fire suppression system includes a body and a shuttle. The body defines an inner volume and is configured to couple with a fire suppression agent source at an inlet, an outlet conduit at an outlet, and further includes a pressure port. The shuttle is disposed within the inner volume. The shuttle is translatable between a first position and a second position. In the first position the outlet is sealed shut and in the second position, the outlet is fluidly coupled with the fire suppression agent source through the inlet and the inner volume. The shuttle is configured to transition out of the first position and into the second position responsive to a decrease in pressure at the pressure port. The pressure port is fluidly coupled with a chamber defined by the shuttle and the inner volume.