A fire detection and actuation system , comprising a detection tube containing a sensing fluid having a first physical condition and a second physical condition, the sensing fluid being in the first physical condition below a temperature threshold and being in the second physical condition above the temperature threshold, wherein the sensing fluid is inescapably sealed within the detection tube , and wherein the sensing fluid is at least partially liquid in the first physical condition; and a sensing device movable to open in response to a transition of a portion of the sensing fluid from the first physical condition to the second physical condition; wherein the sensing device is also movable from open in response to a transition of a portion of the sensing fluid from the second physical condition to the first physical condition; the sensing device is a release valve actuation assembly for use with a pressure pilot valve , wherein the release valve actuation assembly includes an actuation portion having a pin that is movable from a first position to a second position in response to a pressure increase from a transition between the first physical condition and the second physical condition, and the release valve actuation assembly opens in response to the actuation portion being moved to the second position; the release valve actuation assembly further including a bias member , a pilot pressure channel , and a housing that receives the pin ; the pin including a first end in fluid contact with the sensing fluid and a second end in contact with the bias member , and an opening of the pin aligns with the pilot pressure channel when the pin is in the second position such that fluid can pass through the pin in the second position to move the pressure pilot valve . a detection tube containing a sensing fluid having a first physical condition and a second physical condition, the sensing fluid being in the first physical condition below a temperature threshold and being in the second physical condition above the temperature threshold, wherein the sensing fluid is inescapably sealed within the detection tube , and wherein the sensing fluid is at least partially liquid in the first physical condition; and a sensing device movable to open in response to a transition of a portion of the sensing fluid from the first physical condition to the second physical condition; wherein the sensing device is also movable from open in response to a transition of a portion of the sensing fluid from the second physical condition to the first physical condition; the sensing device is a release valve actuation assembly for use with a pressure pilot valve , wherein the release valve actuation assembly includes an actuation portion having a pin that is movable from a first position to a second position in response to a pressure increase from a transition between the first physical condition and the second physical condition, and the release valve actuation assembly opens in response to the actuation portion being moved to the second position; the release valve actuation assembly further including a bias member , a pilot pressure channel , and a housing that receives the pin ; the pin including a first end in fluid contact with the sensing fluid and a second end in contact with the bias member , and an opening of the pin aligns with the pilot pressure channel when the pin is in the second position such that fluid can pass through the pin in the second position to move the pressure pilot valve . <EOS>