An ejector comprising a motive inlet, a motive nozzle separably secured to the motive inlet, a suction chamber about the motive nozzle, a suction fluid inlet to the suction chamber, a mixing tube in fluid communication with the suction chamber and the motive nozzle, a diffuser in fluid communication with the mixing tube and distal the suction chamber and the motive nozzle, and an outlet from the diffuser is provided. A nozzle comprising at least two concentric arc nozzle portions is also provided. An ejector comprising a mixing tube including a flexible layer adapted to compress or stretch, thereby allowing a mixing tube diameter to change is further provided.