Abstract: A continuous flow tube containing a series of emitters arranged to discharge through a wall of the flow tube, each emitter forming a flush flow passage collapsible to form a drip flow passage at a preselected low flow tube pressure; the emitters having side walls of such area with respect to the area of the flow tube, that when exposed transversely to initial flow through the flow tube the emitters form externally a series of flow restricting valves which rapidly raise the flow line pressure to a value at which drip flow occurs, thereby minimizing the number of emitters undergoing flush flow.One embodiment of the emitter is adapted to be installed by forcing the emitter into the flow tube from the exterior thereof. Another embodiment utilizes a flow tube initially in the form of a web which receives the emitters and is then rolled into a tube with the margins of the web circumferentially overlapped and bonded.