A system is provided for an aircraft propulsion system. This system includes an inlet lip, a bulkhead and a piccolo tube for a thermal anti-icing system. The inlet lip extends circumferentially about an axial centerline. The bulkhead extends circumferentially about the axial centerline. The bulkhead is configured with the inlet lip to form a cavity axially between the inlet lip and the bulkhead. The piccolo tube extends circumferentially about the axial centerline within the cavity. The piccolo tube is configured with an elliptical cross-sectional geometry.

A system is provided for an aircraft propulsion system. This system includes an inlet lip, a bulkhead and a piccolo tube for a thermal anti-icing system. The inlet lip extends circumferentially about an axial centerline. The bulkhead extends circumferentially about the axial centerline. The bulkhead is configured with the inlet lip to form a cavity axially between the inlet lip and the bulkhead. The piccolo tube extends circumferentially about the axial centerline within the cavity. The piccolo tube is configured with an elliptical cross-sectional geometry.

A piccolo tube for an anti-icing system may comprise an annular tube and a plurality of openings formed along a circumference of the annular tube. The annular tube may comprise a first cross-sectional diameter at an inlet point and a second cross-sectional diameter at a distal point. The second cross-sectional diameter is less than first cross-sectional diameter. The distal point may be 180° from the inlet point.

A piccolo tube for an anti-icing system may comprise an annular tube and a plurality of openings formed along a circumference of the annular tube. The annular tube may comprise a first cross-sectional diameter at an inlet point and a second cross-sectional diameter at a distal point. The second cross-sectional diameter is less than first cross-sectional diameter. The distal point may be 180° from the inlet point.

Pneumatic air systems for use onboard aircraft include a compressor configured to receive air from an air supply and increase a pressure of said received air to generate compressed air, a heat exchanger configured to receive the compressed air as a first working fluid and a treating air as a second working fluid, the heat exchanger configured to convert the compressed air to compressed and temperature treated air, one or more aircraft systems configured to receive the compressed and temperature treated air, and a surge prevention circuit arranged to prevent surge of air at the compressor, wherein the surge prevention circuit comprises a mechanical valve that is actuated based on a detected pressure within a sense line operably coupled to the mechanical valve.

An anti-icing system of a nacelle inlet of an engine of an aircraft includes first and second direct acting valves and first and second control valve assemblies fluidly connected to the nacelle inlet. The first direct acting valve includes a first inlet, outlet, valve chamber, and piston. The first piston is positioned in the first direct acting valve. The first control valve assembly is fluidly connected to the first valve. The second direct acting valve includes a second inlet, outlet, valve chamber, and piston. The second piston is positioned in the second direct acting valve. The second direct acting valve is fluidly connected to the first direct acting valve in a series configuration. The second control valve assembly is fluidly connected to the second valve chamber.

An anti-icing system of a nacelle inlet of an engine of an aircraft includes first and second direct acting valves and first and second control valve assemblies fluidly connected to the nacelle inlet. The first direct acting valve includes a first inlet, outlet, valve chamber, and piston. The first piston is positioned in the first direct acting valve. The first control valve assembly is fluidly connected to the first valve. The second direct acting valve includes a second inlet, outlet, valve chamber, and piston. The second piston is positioned in the second direct acting valve. The second direct acting valve is fluidly connected to the first direct acting valve in a series configuration. The second control valve assembly is fluidly connected to the second valve chamber.

An aircraft anti-icing system is disclosed. A tube having a plurality of outlet ports is disposed within an interior of an outer housing in spaced relation to a closed end of this outer housing. The exterior of the outer housing includes a leading edge at its closed end. The tube is anchored relative to the outer housing by one or more brackets that extend from the tube to the outer housing. An open end of the outer housing may be closed by an aft wall that encloses the tube within an interior compartment of the outer housing.

An aircraft anti-icing system is disclosed. A tube having a plurality of outlet ports is disposed within an interior of an outer housing in spaced relation to a closed end of this outer housing. The exterior of the outer housing includes a leading edge at its closed end. The tube is anchored relative to the outer housing by one or more brackets that extend from the tube to the outer housing. An open end of the outer housing may be closed by an aft wall that encloses the tube within an interior compartment of the outer housing.

A pressure regulating valve assembly includes: a valve having an upstream side receiving an input flow and a downstream side providing an output flow, an actuator for opening and closing the valve, including partially opening the valve, and a regulator controlling the actuator to open, close or partially open the valve. The regulator includes a sense pressure port, wherein pressure at the port is maintained constant by the regulator. A chamber has a first entry orifice, a second entry orifice and an exit orifice. The first entry orifice is connected to the upstream side, the second entry orifice is connected to the downstream side, and the exit orifice is connected to the port. The exit orifice provides that the pressure at the exit orifice lies between the pressure at the first entry orifice and the pressure at the second entry orifice.