Vocabulary Terms

Question 1

Air Gap

Answer 1

A complete physical separation between the free flowing discharge end of a potable water supply pipeline and an open or non-pressure receiving vessel.

Question 2

Atmospheric Vacuum Breaker (AVB)

Answer 2

An assembly containing an air inlet valve, a check seat and an air inlet port. The flow of water into the body causes the air inlet valve to close the air inlet port. When the flow of water stops the air inlet valves falls and forms a check against back siphonage. At the same time it opens the air inlet port allowing air to enter and satisfy the vacuum. This device cannot be under constant pressure (more than 12 hours). It must be installed at least 6” higher than all downstream piping and the highest downstream outlet. No back pressure may exist. No shut off valves may be installed down-stream of the AVB.

Question 3

Backflow Prevention

Answer 3

The mechanical prevention of reverse flow, or back siphonage, of non-potable water from an irrigation system into the potable water source.

Question 4

Backpressure

Answer 4

any pressure, regardless of its source, against the outlet side of the backflow prevention device, which exceeds the supply pressure against the inlet side of the device. Examples: pressure caused by gravity due to elevation differences; a pump installed in the system; or steam and/or air pressure.

Question 5

Backsiphonage

Answer 5

A form of backflow due to negative or sub-atmospheric pressure within a potable water system.

Question 6

Cross-connections

Answer 6

an actual or potential connection between a potable water source and an irrigation system that may contain contaminates or pollutants, or any source of water that has been treated to a lesser degree in the treatment process.

Question 7

Design Pressure

Answer 7

The pressure that is required for an emission device to operate properly. Design pressure is calculated by adding the operating pressure necessary at an emission device to the total of all pressure losses accumulated from an emission device to the water source.

Question 8

Double Check Valve Backflow Prevention Assembly (DCVA)

Answer 8

Backflow Prevention assembly using two shut off valves and two check valves assembled and pre-tested at the factory, designed to physically prevent the backflow of water. May be used only in non-health hazard conditions.

Question 9

Dynamic Pressure

Answer 9

The pressure of water as it is moving through the system. Also referred to as “working pressure”.

Question 10

Emission Device

Answer 10

Any device that is contained within an irrigation system that is used to apply water. Common emission devices in an irrigation system include spray and rotary sprinkler heads, and drip irrigation emitters.

Question 11

Head radius

Answer 11

Head spacing. Spacing of heads that is equal to the published radius.

Question 12

Health hazard

Answer 12

a cross-connection or potential cross-connection with an irrigation systems that involves any substance that may, if introduced into the potable water supply, cause death or illness, spread disease, or have a high probability of causing such effects.

Question 13

Irrigation Plan

Answer 13

A scaled drawing of a landscape irrigation system which lists required information, scope of the project and represents the changes made in the installation of the irrigation system.

Question 14

Lateral Piping/ Lateral lines

Answer 14

The piping after the remote control valve that is not subject to constant main line pressure.

Question 15

Main Line

Answer 15

The portion of piping, normally under constant pressure, located between the water source and remote control valves or quick coupler valves.

Question 16

Maintenance Checklist

Answer 16

A document made available to the irrigation system’s owner or owner’s rep that contains info regarding the operation and maintenance of the irrigation system, including but not limited to: checking and repairing the system, setting the automatic controller, checking the rain or moisture sensor, cleaning filters, pruning grass and plants away from irrigation emitters, using and operating the irrigation system, the precipitation rates of each irrigation zone within the system, any water conservation measures currently in effect from the water purveyor, the name of the water purveyor, a suggested seasonal or monthly watering schedule based on current evapotranspiration data for the geographic region, and the minimum water requirements for the plant material in each zone based on the soil type and plant material where the system is installed.

Question 17

Master Valve

Answer 17

An automatic or manual valve installed at the supply point, which controls water flow into the system main line piping. If a master valve is installed, it must be installed after the backflow prevention device.

Question 18

Double Check Valve Backflow Prevention Assembly (DCVA)

Answer 18

Backflow Prevention assembly using two shut off valves and two check valves assembled and pre-tested at the factory, designed to physically prevent the backflow of water. May be used only in non-health hazard conditions. Do not confuse a DOUBLE check valve with a DUAL check valve. Although a dual check has two check valves like a double check, it is not an approved form of backflow prevention for irrigation systems.

Question 19

Non-potable Water

Answer 19

Water not suitable for human consumption.

Question 20

Precipitation Rate

Answer 20

also known as application rate. The rate at which water is applied by the irrigation system. It is usually measured in inches per hour. The following formula is used to figure precipitation rate. GPM( full circle head) x 96.3 divided by Head spacing x Row spacing OR total GPMx 96.3 divided by total area.

Question 21

Pressure Compensating Spray Head

Answer 21

A spray head used in a method of maintaining a constant discharge pressure regardless of inlet pressure.

Question 22

Pressure Differential Relief Valve

Answer 22

A valve that will open when the inlet pressure exceeds a pre-set pressure.

Question 23

Flush Valve

Answer 23

Flush valves are used primarily in drip irrigation systems. The flow rates for drip systems are usually very low and, as a result, sediments can accumulate on the bottom of the drip tubing due to the slow velocities. A flush valve is a point on the drip line that can be opened to increase the flow of water and the velocity. A ball valve, gate valve or a capped off section of tubing can serve as the flush valve. The flush valve should be installed as far as from the water’s entry point as possible.

Question 24

Head/Sprinkler Head

Answer 24

sprinkler heads can be broken down into three categories: spray, bubbler and rotary. Many people are familiar with these types of emission devices. When designed properly, a sprinkler system can be fairly efficient, however, high evaporation and run-off are always a problem with these systems due to the fact they project water through the air.

Question 25

Sleeve

Answer 25

piping or conduit under hardscape provided for irrigation system piping or wiring. Generally sized 2 sizes larger than the irrigation piping required. If in a high traffic area, it is recommended the sleeve be at least schedule 40 pvc.

Question 26

Solvent

Answer 26

a material that causes a partial dissolving of pvc pipe and fittings so a chemical fusion occurs between the pipe and fitting.

Question 27

Velocity

Answer 27

The speed at which water travels through piping.

Question 28

Water hammer

Answer 28

A shock wave in the piping system usually created by an excessive flow velocity and a fast closing valve. Increased back pressure of the shock wave could result in unwanted backflow.

Question 29

Permanent Sticker

Answer 29

contains the irrigator’s name, license number, company name, telephone number and dates of the warranty period is to be affixed to each controller. If the system is manual, then the sticker goes on the maintenance checklist. Info on the sticker must be printed with waterproof ink.

Question 30

Shrub Spray Heads

Answer 30

installed in landscape bedding. Shrub heads on risers are used in areas where tall vegetation poses a small problem to the irrigator. In order to clear the foilage of the plant material, the spray nozzle is sometimes mounted on a riser that extends out of the ground high enough so the head can function without the spray being distorted. The riser needs to be rigid. Irrigators can make it out of pvc, copper or a purchase manufactured risers. Rigid risers create a potential hazard and should be installed against walls or other types of permanent structures to reduce the threat of injury, vandalism and liability. 12” pop up heads are available for flowerbed applications as well, and would minimize the hazard of risers.

Question 31

Spray Heads

Answer 31

spray heads have a fan-shaped pattern that constantly delivers water throughout the pattern as it runs. Spray heads are extremely versatile and offer the irrigator many different solutions to irrigate the given area. Spray heads are best used when installed in smaller turf areas, but they can certainly be adapted to irrigate larger areas. A Spray head functions by discharging a fine, uniform spray. The larger droplets irrigate the area furthest from the head while the smaller droplets and “fall-out” mist waters the areas nearest the head.

Question 32

Walk-through (final)

Answer 32

to conduct a final walk through to explain the operation of the irrigation system.

Question 33

water conservation

Answer 33

it is up to the irrigator to educate the homeowner on techniques and devices to conserve water. this would include making the homeowner aware of drip irrigation, rain sensors, soil moisture sensors, etc. Educating the homeowner about precipitation rate, soil infiltration rate and evapotranspiration rates will enable them to water more efficiently. Everyone in the irrigation industry must make the efford to promote conservation of water at all times. In times of drought and low water supplies, the first thing to go will be luxuries and that is what an irrigation system is. drip irrigation, pressure regulating heads, pressure regulating valves, low-angle spray heads, and proper irrigation scheduling will greatly reduce water waste.

Question 34

Main line piping

Answer 34

some contractors adhere to the practice of installing the mainline first due to the depth of the mainline. With the mainline having static water (assuming no master valve), it requires special attention to depth due to freeze line considerations.

Question 35

Non-Health Hazard

Answer 35

a cross connection or potential cross connection from a landscape irrigation system that involves any substance that generally would not be a health hazard but would constitute a nuisance or be aesthetically objectionable if introduced into the potable water supply.

Question 36

Static Water Pressure

Answer 36

the pressure of water when it is not moving.

Question 37

Zone Valve

Answer 37

an automatic valve that controls a single zone of a landscape irrigation system.