US Patent 9915480 Tube assembly

A tube assembly that may be for a fuel nozzle of a fuel system of a gas turbine engine may have a first tube defining a first flowpath along a centerline, a second tube generally spaced radially outward from the first tube with a first void located between and defined by the first and second tubes, and a support structure located in the first void and extending between the first and second tubes. The support structure is constructed and arranged to minimize or eliminate thermal conduction between the tubes. The entire assembly may be additive manufactured as one unitary piece. One example of a method of operation may include designed-for breakage of the structural support due to then al stresses thereby further minimizing thermal conduction between tubes.