The Bowsmith NonStop Emitter design, patented in 1974, is based on a unique principle not found in any other emitter. This Pressure Cascade Principle allows the emitter to tolerate large amounts of suspended solids in irrigation water without clogging and without the need for fine-mesh filter screens. For over 40 years, millions of Bowsmith NonStop emitters have proven that the unique NonStop Continuous Self-Cleaning Action (Pressure Cascade Principle) truly works, even under conditions that would quickly clog ordinary emitters. With only 30-mesh filtration (recommended minimum), Bowsmith NonStop emitters have successfully operated with water containing heavy concentrations of sand, silt, iron bacteria “slime”, calcium carbonates, and even algae and moss.