The unique design of the Netafim Techflow Emitters regulates flow and provides continuous self-cleaning action during operation. These emitters have a 2.2 PSI internal check valve that helps prevent low emitter drainage holding back up to a 5 ft column of water. The anti-siphon operation prevents contaminants from being drawn into the emitter. The Techflow Emitters are pressure compensating and deliver the same flow from 14.5 to 58 PSI.