Abstract: A flow device for interaction with a fluid stream to control its direction comprises a conduit system which includes a cavity in communication with an inlet for the stream and at least one outlet for the stream. Controllable flexible means co-operative with the cavity are provided for interaction with the stream and function to deflect the stream in one direction or the other from its entering direction as it leaves the cavity. The fluid stream can be selectively directed into one or the other of two separate outlets, or a single outlet can be combined with a vortex arrangement so as to enable one to select the direction of rotation of the stream about the axis of the vortex.