Patent ID: 8425188

Claim:
A diffuser pipe assembly ( 28 ) of a gas turbine engine including a plurality of circumferentially spaced diffuser pipes ( 38 ), each diffuser pipe ( 38 ) comprising a substantially truncated conical inlet end section ( 46 ) defining an inlet end ( 40 ) of the diffuser pipe ( 38 ) and a curved section ( 48 ) defining an exit end ( 41 ) of the diffuser pipe ( 38 ) to direct a pressurized airflow from the inlet end ( 40 ) through the diffuser pipe ( 38 ) to the exit end ( 41 ), the curved section ( 48 ) having a cross-section expanding rearwardly towards the exit end ( 41 ) such that the curved section ( 48 ) presents a curved fishtail profile, the inlet end section ( 46 ) defining a depressed local area ( 58 ) in a pipe wall of the inlet end section ( 46 ) such that both inner and outer surfaces of the pipe wall in the depressed local area ( 58 ) are bent into the diffuser pipe ( 38 ), wherein each consecutive cross section area Sn+1 is bigger than or equal to a preceding one Sn.