Quick facts about drip irrigation

Quick Facts Sheet about drip irrigation and Glossary:
 

Micro-irrigation is a low pressure, low volume irrigation system suitable for vegetables, shrubs, flowers, and trees.

Micro-irrigation has been gaining attention because of its potential to increase yields and decrease water use, fertilizer, and labor requirements if managed properly.

Micro-irrigation or low volume irrigation systems can be subdivided into three categories, according to uses:
A. Drip irrigation
B Micro-sprinklers
C. Drip tape

Drip irrigation is the slow application of water directly to the plants' root zone in a predetermined pattern. Maintaining an optimum moisture level in the soil at all times results in less water lost to the sun and the wind. No water is wasted on non-growth areas, and the root zone is maintained at its ideal moisture level, combining the proper balance of water and air for a very efficient irrigation system.

Micro sprinklersare designed for placement in both new and existing landscape or in agriculture areas, and are ideal for use on difficult terrain such as on slopes, in oddly shaped areas, and in orchards, greenhouses, and nurseries. Micro-sprinklers operate at low pressure and have a wide range of flow rates (5 to 50 GPH) and diameters (3 to 30'). Micro sprinklers have small droplets and a low application rate. Micro-sprinklers can prevent plant stress by maintaining low water tension in the soil.

Drip Tape is a flat tape with drippers pre-inserted in a spacing of 12" to 18". The drip tape expands when filled with water and is ideal for use in vegetable gardens or for row crops or where total saturation of coverage is desired. The drip tape is used with special drip tape fittings. Drip tape fittings are different in design from those used with drip hose in that they work with a twisting lock device rather than with compression.

System Layout
 

Micro-irrigation systems consist of a head or head assembly and a distribution network. The head or head assembly consists of a controller, pump (if needed), backflow device, valve, fertilizer injector, filter, and pressure regulator. The fertilizer injector is optional but highly recommended; the controller is necessary only if the system is to be automated.

Drip Irrigation Valve Assembly consist of Battery operated controller with hose or pipe thread, fertilizer injector, 150 mesh 3/4" filter, 25 PSI preset pressure regulator and 3/4" spin-lock swivel adapter.

Micro-irrigation distribution networks consist of mainline pipes, usually made of PVC, sub laterals made of polyethylene (PE), then the PVC fittings, drip fittings (barb, compression or spin-lock), then the watering device such as drippers or emitters, micro-sprinklers, and drip tape, and last the accessories such as hose end, goof-plugs, and punches.
Drip irrigation line consist of 3/4" compression 3/4" swivel adapter, 1/2" barb connector, PC dripper, 1/2" compression coupling, Netafim PC dripper, 1/2" spin lock connector, adjustable spray jet, nut-lock connector and 1/2" drip hose

Glossary:
 

Backflow Device: a devise which keeps water that has passed through it from returning into the water source. A valve, usually plastic or brass, allows the flow of water only in one direction. It will prevent a backflow of water into the potable water supply and keep the water supply from becoming contaminated. Always try to use one. Some areas mandate the use of a backflow device in local building codes.

Filter: a plastic device with a screen element inside that installs at the beginning of the system and protects the small orifices of the drippers and micro sprinklers from clogging. Periodically the screen needs to be removed and rinsed to keep the filter clean. Filters are available with different types of screen with mesh from as low as 40 to as high as 300.

Mesh: A way to measure a filter screen, and how fine or small the water passages through the screen are. It is a measuring unit of how many holes the screen has per 1"; the higher the number of holes in the screen, the finer the screen is. A 200 mesh screen filters out smaller dirt particles than a 100 mesh screen.

Pressure Regulator: A device which is preset or adjustable to control the water pressure allowed into the supply line a must with a drip system.

GPH: Gallons per hour. Used to measure the flow rate of low volume irrigation drippers or micro sprinklers

GPM: Gallons per minute. Used to measure the flow rate of the entire irrigation system or valve and sprinkler heads.

PSI: Pounds per square inch in static water pressure is used to measure pressure.

Drip Emitter: Button or flag drip emitter devices will provide a preset flow at a recommended pressure of 15 PSI; in other words, the higher the pressure, the more flow the dripper will give, and the lower the pressure, the less flow the dripper will give.

Micro Sprinkler: Micro sprinklers are a spinner type watering device that are available in a variety of styles and configurations and, like drip emitters, operate at a low-pressure range of 15 to 30 PSI and are rated by flow rate and wetting diameter.

Micro Tubing: 1/4" micro tubing, sometime referred to as distribution tubing, serves as an individual feeder line to deliver the water to each dripper or micro sprinkler. The micro tubing is available in two basic materials, vinyl and polyethylene. The vinyl is soft and the poly is hard.

Pressure Compensating Dripper or PC Dripper: Drippers that provide equal flow at any pressure between as low as 7 to 10 PSI to high as 50 to 60 PSI.

Compression Fittings: Type of fitting into which the drip tubing fits. The fit is tight and when the water is turned on the pressure helps push the tubing against the fitting which increases the holding power. The fitting itself will have a sharp edge inside which is angled backwards, keeping the tubing from being pushed out by the water pressure.

Drip Tape: A thin wall drip line with drippers pre-inserted into the line at various spacing, or with water passages along the line.

Laser Drilled Hose: A 1/4" polyethylene micro tubing with laser drilled holes at preset spacing.

MHT: Male hose thread configuration of a fitting or device.

FHT: Female hose thread configuration of a fitting or device.

NPT: National pipe thread configuration of a fitting or device.