Landscape Irrigation: Chpt 3 Irrigation Components (Texas Irrigation License) 2024 updated

Landscape Irrigation: Chpt 3 Irrigation Components (Texas Irrigation License) 2024 updated Sprinkler Heads: - CORRECT ANSWER-There are several factors in determining which sprinkler heads to use for different areas. * The size/shape of the area to be irrigated * The type of landscaping- -trees -shrubs -turf and or -groundcover *Climate * Slope and * Soil type are all factors to consider It is important never to mix different types of sprinklers on the same zone (or section): - CORRECT ANSWER-The reason for this is that different sprinkler types have varying precipitation rates Matched PrecipitationMost sprinklers available today have matched precipitation which allow for uniform distribution of water: - CORRECT ANSWER-" " means that all sprinkler heads within a watering zone will produce similar precipitation rates, regardless of the pattern (or arc) they cover. For example, if a full circle (360 degree) head delivers 4 gallons per minute (GPM), then a half circle (180 degree) head of the same type will produce half that amount, or 2 GPM. The full circle head has twice as much area to cover, therefore, it needs to put out twice the amount of water as the half circle head Depending on the manufacturer, matched precipitation can be achieved by mixing various arcs/or radii on the same watering zone: - CORRECT ANSWER-Sprinkler heads with varying radii, that are mixed on the same watering zone, should be Spaced with like radii in order to maintain the uniform distribution of water/consistent head spacing within that zone. Unless the manufacturer offers matched precipitation within the arc/radii, mixing heads with varying radii on the same zone should be avoided Most sprinkler head manufacturers will convey a minimum head pressure ( in order for the head to operate efficiently), an operating pressure range/or an optimum head pressure for a specific model head: - CORRECT ANSWER-The nozzle discharge rate/radius can vary significantly depending on the pressure to that head. For example, the following samples of several different nozzle selections show the various discharge rates (in GPM)/radii when the pressure to the base of the head varies: Sample Nozzle Performance ------Pressure---Radius---GPM ----------PSI------------------ Rain Bird --15-----9-------0.45- 2' Quarter--20----10------0.53- MPR Nozzle-25----11------0.60- -----------30----12------0.65- ************************************* Toro Fixed--20----13------1.37- 15' Half MPR-30----15------1.65- Nozzle------40----16------2.02- ------------50----16------2.14- ************************************** Irritrol 17' Full-20---14------2.90- Pro Van ------30---16------3.60- Nozzle-------40---17------4.10- -------------50---17------4.60- The actual head pressure should not: - CORRECT ANSWER-Be much higher than the optimum head pressure or pressure range stated by the manufacturer. Greater pressure at the heads will result in: - CORRECT ANSWER-A greater flow, and throw, of each head (as seen in the sample nozzle performance chart) This is acceptable if calculated into the design. Excessive pressure at the head may: - CORRECT ANSWER-Result in a pattern distortion/wasted water (through evaporation) due to a "misting or fogging" effect at the head. This adverse effect can be corrected by the use of a pressure regulator or By using pressure compensating heads -which provide for a constant discharge pressure at each head regardless of the inlet pressure Pressure compensating nozzles allow for greater uniformity within a zone. Example: too much pressure at the head causing misting/or fogging effects There are many different types of sprinklers heads available from a number of manufacturer's. However, most will fall under one of these 4 Categories: - CORRECT ANSWER-* Spray * Rotary * Bubblers (including drip irrigation)