• Systems should be sized according to the flow rate recommendation of each category (valve, filter and pressure regulator) and not selected by pipe size alone.
• Calculate pressure loss for main line, laterals, fittings, and elevation changes much the same way as for a sprinkler system
• Make sure proper system hydraulic designs are sufficient to allow for a minimum of 15 psi of water pressure at the and of the laterals

• Controllers should be selected with care, especially if it will be running both drip zones and sprinkler zone. The ideal controller will have an independent program for each valve, or two to four programs for a flexibility with each zone.
• Standard electric remote control valves model 33-xxx or a model 510.xxx battery operated controller can be used in the installation, however, care should be taken to review the flow characteristics of the zone that it will be accommodate
• The control valves need to be flushed after installation, and the system pressure must be tested

Nearly all water sources can be made suitable for micro irrigation by means of appropriate physical and/or chemical treatment. Physical treatment is the removal of organic suspended solids which are large enough to block emitter outlets. Suspended solids may be removed by means of a centrifugal separator, screen filter, disk filter, or some combination of the above. Where source waters containing substantial solid loads are used without adequate physical treatment, clogging will usually occur, leading to uneven water distribution and poor system performance. Chemical treatment is the addition of one or more chemicals to the water supply for the purpose of controlling biological growths or chemical reactions. Chemical treatment may be performed alone or in conjunction with physical treatment. Chemical treatments commonly used in micro irrigation systems include the addition of chlorine and /or acid in low percentage to the water supply.

 

Clogging factors can be classified into three main categories:

• Inorganic suspended solids
• Organic (biological) matter (algae and bacteria)
• Sediments generated by chemical reactions

The various water quality problems encountered in operating micro irrigation systems are outlined below. In some situations, two or more of these problems may be present, giving rise to more complex treatment procedures.

1. Presence of large particles in the water supply.
2. Presence of high silt and clay loads in the water supply.
3. Growth of bacterial slime in the system.
4. Growth of algae within the water supply or the system.
5. Precipitation of iron, sulfur, or calcium carbonates.

Filtration Requirements:

• Well or potable water: 155 mesh filter on main line or with backup filter after the electric remote control valve to the laterals on each zone (see filters)
• Water with sand: sand separator on the main line after the back flow device
• Treated sewage water: discs filter model 17xx.150, followed by screen filter model P60 through P80 with 155 mesh
• Water with sand: screen filter 155 mesh after the valve

• Make sure the main filter is installed in an easily accessible location after the backflow device with space to clean the filter manually (see detail)
• Make sure 3/4" or 1" filters below grade are installed after the electric remote control valve with cover upward off center to allow space to open and removed screen elements for periodic cleaning (see detail)
• The Screen filters, disc filters and sand separators need to be flushed after installation.

To achieve optimal performance and less stress on the drip line, drippers or micro sprinklers, you must install a pressure regulator after the filter. Pressure regulators will reduce the operating pressure to the ideal working pressure for low volume irrigation. Pressure regulators are installed below grade downstream after the remote control valve and filter.

1)  3/4" adjustable pressure regulator with flow rates from .2 to 22 gpm for a zone with 3/4" or 1" valve
2) Small size preset pressure regulator with flow rates with up to 10 gpm for a zone with 3/4" valve
3) To assure proper operation of the drip line, take a pressure reading at the and of the line while the zone is on, and make sure 
that the minimum pressure is not lower than the system recommendation

Pressure Regulator Flow Rate Recommendation

Recommended pressure for A1: 25 to 45 psi, use model 18-007 adjustable pressure regulator 28 to 60 psi for up to 20 gpm Recommended pressure for TOP: 30 to 45 psi, use model 18-007 adjustable pressure regulator 28 to 60 psi up to 20 gpm or 18-030 preset pressure regulator with flow rate up to 10 gpm Recommended pressure for button dripper .5, 1 and 2 gph: 15 to 25 psi, use model 18-007 adjustable pressure regulator 17 to 35 psi for up to 20 gpm or 18-020, 18-025, 20 and 25 psi preset pressure regulator with flow rate up to 10 gpm

See flow rate chart for 3/4" preset pressure regulator Item catalog list:

See design detail of 3/4" AC valve with screen filter, and pressure regulator below grade installation 33-014

See design detail of 3/4" battery operated controller, screen filter, and pressure regulator 510-075

Note: after installing the valve, screen filter and pressure regulator, the zone assembly, needs to be flushed before connecting to the lateral.

In low volume irrigation 1/2" low density polyethylene tubing is typically used for lateral piping. Once you determine the number of drippers and total flow rates, make sure not to exceed the hydraulic constraints of each lateral.

See flow rate and velocity recommendation for individual 1/2" drip laterals

Drip tubing item catalog list:

• 1/2" drip hoses are available in different inside and outside diameters, make sure to use the correct fittings. DIG uses color coded fittings: color red with .450 OD, green with .620 to .630 OD, black with .700 OD and blue with .710 OD
• The drip lateral need to be flushed after installation and the system pressure must be tested

See flow rate and velocity recommendation for PVC pipe

Drip insert items catalog list:

Installation of A1pc Drip Line

Installation of TOP 12 outlet drip head

Installation of single outlet drippers

Installation of micro sprinklers

Calculating water requirements for an individual plant using single outlet drippers or TOP

Calculating water requirements for dense plantings using A1 drip line

Flush mains and sub-mains during installation. Connect drip lateral to main line and flush with end of drip line open. Place a flush valve or ball valve at the end of the line (See design detail)