Patent ID: 8356486

Claim:
An auxiliary power unit (APU) comprising: a compressor that compresses air flowing into the APU; a combustor connected to the compressor to receive a portion of the compressed air; a turbine for receiving combustion gas from the combustor; an exhaust downstream of the turbine; and a bleed air valve that modulates a flow of air bled from the compressor, the bleed air valve comprising: a primary conduit connected between the compressor and a pneumatic system; a secondary conduit in flow communication with the primary conduit and connected to the exhaust; and a flow inhibitor arranged within the primary conduit and movable between a first position that allows the bleed air to flow through the primary conduit to the pneumatic system and substantially prevents the bleed air from flowing into the secondary conduit and to the exhaust, and a second position that substantially prevents the bleed air from flowing through the primary conduit to the pneumatic system and allows the bleed air to flow from the primary conduit into the secondary conduit and to the exhaust; wherein the secondary conduit comprises a tube with a free inlet end protruding into the primary conduit, wherein the free inlet end is blocked in the first position and open in the second position.