Apparatus and system having an over temperature fuse in a signal tube for a gas turbine engine

Abstract

Apparatus comprising a signal tube extending from an engine component on a hot side of a firewall in a gas turbine engine to an engine control mechanism disposed on a cool side of the firewall. The apparatus includes a fuse in the portion of the signal tube extending through the hot side. An exemplary fuse includes a temperature-sensitive inner member that is deformable upon exposure to temperatures greater than a predetermined temperature. The fuse is operative responsive to a breach in the signal tube to change from a first condition to a second condition to prevent an over-temperature situation on the cool side of the firewall. An outer member substantially enclosing the inner member provides information about the condition of the fuse. A system utilizing the fuse includes a gas turbine engine having a firewall separating a hot side from a cool side, an engine control mechanism disposed on the cool side, and a signal tube extending from a component on the hot side to the engine control mechanism. The engine control mechanism operates the engine with a first operating logic utilizing a pressure signal related to a static pressure of a fluid in the signal tube. Loss of the pressure signal causes the engine control mechanism to change to a second operating logic which does not utilize the pressure signal.