The Bowsmith NonStop emitter design, patented in 1974, is based on a simple unique principle found in no other emitter. This Pressure Cascade Principle permits the emitter to tolerate large amounts of suspended solids in irrigation water, without clogging and without the need for fine-mesh filter screens.
- The flow path is a series of orifices in the silicone diaphragm.
- In normal operation, the total pressure difference between inlet and outlet is divided equally across each of the orifices in the flow path.
- For example: 20 psi inlet pressure, and 10 orifices in the flow path, the pressure drop across each orifice is 2 psi.
- If an obstruction should occur in any of the orifices, the flow through that orifice will be momentarily restricted. As a result, the pressure drop across that orifice will increase, causing the orifice to enlarge until the obstruction has passed.
For over 40 years, millions of Bowsmith NonStop emitters have demonstrated that the unique NonStop Continuous Flushing Action (Pressure Cascade Principle) really works, even under conditions that would quickly clog ordinary emitters. With only 30-mesh filtration, Bowsmith NonStop emitters have operated successfully with water containing heavy concentrations of sand, silt, iron bacteria 'slime', calcium carbonates, even algae and moss. To the grower and contractor this means:
- Reduction in plant loss and stress.
- Lower capital investment in filtration equipment.
- Lower labor costs for filter maintenance and overall system maintenance.
The use of very fine mesh screen (140 - 200 mesh) filtration that is necessary for ordinary emitters is not recommended for Bowsmith NonStop emitters.
Why? Because of the necessity for frequent cleaning of the filters.