Irrigation

When a longer than usual electrical run for irrigation systems is requested, most contractors use?

#12

Under normal conditions what is the most common wire size used for low voltage irrigation systems?

#14

At what trajectory would your head be for watering under shrubs?

0"

If a 1' column of water, 1/2" pipe exerts 0.433 PSI at the bottom, what will 1' of 1 1/2" pipe exert

0.433 PSI

The common wire on a electrical irrigation system must be as or ___ larger than the control wire?

1 Size

What is the smallest size most contractors use in irrigation systems?

1"

Spray heads have a precipitation rate ranging from?

1"-2" per hour

Spray heads have a radius of between?

1' - 16'

As the water comes out of the sprinkler head, it travels through space to the ground. The angle at which the water leaves the head is trajectory of spray. Trajectories of spray include?

1) 0 Trajectory - This flat spray can be used for throwing water under low shrubs and on tops of hills. 2) 10 Trajectory - This low-angle spray can be used under windy conditions for shrubs, ground cover bed, and turf. 3) 25-28 Trajectory - This is the standard trajectory that most sprinklers throw for use on turf. 4) 35 Trajectory - This is a stream spray used for watering ground cover, shrubs and turf.

Dividing an irrigation design includes:

1) Areas that share similar plant water needs 2) Soil Permeability rates 3) Sun or shade conditions 4) Slope conditions

Backflow prevention devices

1) Atmospheric Vacuum Breaker (AVB) - Installed between the circuit valve and sprinklers 2) Pressure Vacuum Breaker (PVB) - Installed after the water meter and before any valves. 3) Double check Valve Assmbly - Much more advanced then the (PVB) and Installed after the water meter and before any circuit valves. 4) Reduced Pressure Principle Backflow Preventer (RPP) - super advanced system used in area where lots of toxic chemicals are in the irrigation system. 5) Hose Connection Vacuum Breaker (HCVB) - Effective against back siphonage.

What causes Surge Pressure/Water Hammer?

1) Automatic valves that close too quickly 2) Closing a manual valve too quickly 3) Filling an empty pipe with water 4) A water velocity in excess of 5ft (1.5 m) per second

The advantages of a Drip Irrigation system is:

1) Components are not very expensive, so money can be saved. 2) It puts the water at the plants root zone where it is needed 3) There is no water runoff with drip irrigation because of the slow application, nearly all water soaks into the soil. 4) Water is not thrown into the air, it is in the sprinkler system, so there is no evaporation in the air from plant leaves. 5) There is less weed growth because the water is placed only at the plant's roots, in contrast to covering a large area with sprinkler heads.

If we discover our irrigation heads making some areas quite wet and other are relatively dry, then we are going to encounter turf problems such as:

1) Dead patches 2) Uneven color 3) Fertilizer damage (after spreading fertilizer, many people turn on their irrigation systems to wash the feritlizer into soil so that leaves are not burned by the chemicals) 4) Disease caused by overwatering

What is the Four step process of designing a drip irrigation system?

1) Determine Watering Frequency 2) Determine Plant Water Need 3) Determine the number of watering circuits 4) Determine the number of emitters

Why is Triangular Spacing an advantage?

1) Equilateral triangular spacing produces a more uniform water distribution pattern. With a square layout, the sprinkler heads have to be closer to get adequate coverage in the center of the sqaure 2) Because the water distribution pattern is more uniform with triangular spacing, there is less water waste. 3) Sprinkler heads are spaced further apart in triangular spacing, thus resulting in the use of fewer heads on a project

Flow Characteristics

1) Friction loss 2) Velocity 3) Surge pressure

With wire sizing you must consider?

1) How far are the valves from the controller? 2) What is the static water pressure at the valves? 3) How many valves are on the same controller station?

When selecting a valve you consider:

1) How many gpm (L/min) of water is the circuit demanding? 2) How much pressure can you afford to lose? 3) Have you installed the main pressure line deeper than the lateral lines? (will you need an angle valve?) 4) Are you using an electric or hydraulic system? 5) Is the area prone to lightening strikes?

When should you use low angle nozzles?

1) On slope tops 2) When you have low overhead clearance such as mature trees and bridges 3) In high wind areas

What are the 2 types of plastic pipes?

1) PVC (Polyvinyl chloride) pipe 2) PE (Polyethylene) pipe

What is the most common type of back flow preventers?

1) Reduced pressure backflow 2) Pressure vacuum breakers 3) Double check valves

Water Pressure

1) Static pressure (Valve is closed) 2) Working pressure (dynamic pressure)

Friction loss occurs when:

1) The length of the pipe increases 2) The roughness of the inside of the pipe increases 3) The speed of water flow increases

To calculate working water pressure... you do?

1) The loss of pressure as water flows through pipe 2) The loss of pressure as water flows through valves 3) How changes of elevation effect water pressure

Circular patterns which make up the largest group of sprinkler heads, are defined by the following characteristics:

1) The radius of water thrown 2) The arc of the water pattern 3) The trajectory of the water as it is thrown from the sprinkler head

A plant's water need is affected by:

1) Type of plant 2) Location in sun or shade 3) Proximity to trees and tree roots

Static water pressure in any area can be determined by?

1. Calling the water supplier/Utility Company 2. Calling Fire Department 3. Checking it yourself with a proper gauge

Components of a public water delivery system are:

1. City Main 2. Water Meter 3. Service Line

If head placement is not done properly turf problems arise, which would be?

1. Dead patches 2. Uneven color 3. Disease and fertilizer damage

When sizing wire for irrigation systems you should consider:

1. Distance from valves to controller 2. Static water pressure at valves 3. Number of valves on same controller

When calculating flow of working pressure, what don't do you do?

1. Don't go beyond 75% if maximum safe flow for the meter 2. Don't exceed 10% of the static water pressure 3. Don't go beyond velocities of 5'-6' per second

What are the 2 types of Rotary Sprinkler Heads?

1. Impact Drive Heads 2. Gear Drive Heads

Main causes of friction loss are:

1. Length of pipe 2. Roughness inside the pipe 3. Speed of water flow increases

A 1,000 Square Foot Shrub installation needing 1.5 inches of water each week is irrigated by a system that delivers 5.2 GPM. How much irrigation running time is needed to deliver 1.5 inches of water?

1. PR = 5.2GPM X 96.3/1,000 SF = 0.5 inches per hour 2. 0.5 inches per hour/60 minutes = 0.008 inches of water per minute 3. 1.5 inches/0.008 inches per minute = 188 minutes of operation 4. 188 minutes/60 minutes = 3 hours and 8 minutes of operation

Circular Pattern heads are defined by:

1. Radius of water flow 2. Arc of water pattern 3. Trajectory of water from the head

When designing an irrigation system, what factors are most important?

1. Similar plants water needs 2. Slope conditions - Sun or shade conditions 3. Soil permeability

What are the 2 types of sprinkler heads?

1. Spray heads 2. Rotary heads

What are the 2 types of irrigation systems

1. Sprinkler Irrigation 2. Trickle Irrigation

Surge pressure is determined by knowing what factors?

1. Water velocity in feet per second 2. Valve closure time in seconds and tenths of a second 3. Length of pipe in feet

Good practice when wiring valves is to leave an extra ___ for repairs?

1.5'

What type of rotary sprinkler head is generally used less frequently?

1/4 Circle

At what trajectory would you need for windy conditions?

10"

What size valve box is common in commercial landscaping?

10'-12'

Head to head coverage will cover what percent of the radius?

100%

Rotary gear drive heads pop up from ?

2 1/2' - 4'

According to the irrigation industry a single sprinkler can supply enough water to grow green grass for only ___ of the radius of water throw?

2/3

If the difference in water pressure is more than ____ % from the list sprinkler to the farthest, this will cause problems in watering?

20%

In a drip irrigation system the maximum variation of pressure between the first emitter and the last emitter should be less than ____ to get a uniform GPH flow?

20%

A transformer in the controller of an electric valve reduces 120V to what?

24V

At what trajectory would you need for turf or standard angle?

25" - 28"

On a planter 8' in diameter, how many linear feet of curbing is needed to go all the way around the planter?

25.12

What trajectory would be considered stream spray for ground cover, shrub or turf?

35"

How many 90' heads do you need to cover a 9' area?

4

When the trenches are back filled after pipes are laid and tested if need be, what amount of back fill should be placed before tamped?

4" increments

You have a 20' drop in elevation from the main line with a constant static pressure of 43 PSI, it's a 100' run to the valve, what is the PSI at the valve?

43 PSI + 20 X 0.433 static pressure at valve = 51.66 PSI

If you have a 100' vertical line from a water service, when it hits the horizontal run, what is the PSI coming out?

43.3

Rotary heads have to run ____ times as long as spray heads to deliver the same amount of water?

5

Pipe sizes are selected based on a flow velocity rate of?

5 FPS

When digging a trench for pipe placement a trenching machine is able to trench?

5' to 30' per minute

It is only necessary to wet ____ of the root zone of most plants to provide the benefits of irrigation?

50%

The maximum radius a spray head can cover is?

6'-8'

Precipitation rate in millimeters per hour =

60 X the total (heads X L/min) in a given area/Square meters of the area being covered

What is the effective radius of coverage for a single head?

60% of its effective radius

What is a typical water pressure available in a city environment?

65 PSI

Some types of impact heads can throw water up to...?

650'

A 7' drop in elevation will cause what increase in PSI?

7 X 0.433 = 3.03 PSI

Precipitation rate in inches per hour =

96.3 X the total gpm in a given area/Total square feet of the area being covered

Scheduled Rated Pipe

A PVC pipe used as a covering or sleeve for thinner, weaker pipe when it passes beneath walks, roads, driveways, or walls. The higher the schedule rating is, the stronger the pipe will be.

Pressure Rated Pipe

A PVC pipe used to carry the water through an irrigation system. It is produced in 4 forms. Each form is guaranteed to withstand a particular water pressure of either 125, 160, 200, or 315 pounds per square inch (PSI).

Lateral Line

A secondary irrigation line that carries water from valves to irrigation heads

Surge Pressure

A shock wave type of pressure that results when water velocity is too high and then is suddenly stopped. Excessive surge pressure over time will weaken the pipe and connections with an irrigation system.

To get even water distribution we must overlap sprinkler spray patterns because:

A single sprinkler can supply enough water to grow green grass for only 2/3 of the radius of water throw. The outer 1/3 of the area covered does not receive enough water to sustain good plant growth.

How is pipe sized for irrigation?

According to how much water can go through it

Drip Irrigation Filters

All drip systems need to filter to keep small particles in the water from clogging the emitters.

Drip irrigation

Also known as trickle irrigation, micro irrigation or localized irrigation, is an irrigation method that saves water and fertilizer by allowing water to drip slowly to the roots of plants, either onto the soil surface or directly onto the root zone, through a network of valves, pipes, tubing, and emitters. It is done through narrow tubes that deliver water directly to the base of the plant.

What is a water window?

Amount of time available for irrigation

What is a zone?

An area covered by a group of heads connected to a control valve

Geographical Area

An area of the landscape with a specific water need, based upon needs of the plants growing there and the rate of water absorption by the soil. A landscape may contain numerous and different geographical areas.

What is a controller?

An electric timing device that operates each zone for a predetermined time and frequency

What is backflow of water?

An irrigation system needs a device that will keep water from flowing back into the potable water supply. These devices are called backflow preventers, and they prevent the reverse flow of water.

What kind of valve is best when the valve is located below the lateral lines?

Angle

Why do golf courses usually use hydraulic systems rather than electrical systems?

Because of frequency of lightning strikes

To prevent fungus growth, you should water your lawn?

Before sunrise (4:30AM - 6:00AM)

The type of wire used for irrigation systems are UF, and when extra wires are run for repairs or other needs, will usually be what color?

Blue

Low voltage wire for electric valves can be?

Buried in the ground

When pipe is run at the same elevation this allows the pressure to remain the same. If there is a rise or fall in elevation, what would this do to the pressure?

Change 0.433 per foot

What type of head is best for curvilinear, rectilinear and square areas?

Circular

Which patterns make up the largest group of sprinkler heads?

Circular

The Filter, Pressure regulator and Drip Tubing are considered what?

Components of a drip system

A spray head will...?

Cover a smaller area and distribute a lot of water resulting in high precipitation levels

What is the first step in head selection?

Determine the available operating pressure range for sprinkler heads

When wire in a low voltage irrigation system is wrapped six to eight times around a 1" piece of PVC this is to?

Dissipate power if hit by lightning

What does spray diffusion result in?

Distortion of the sprinkler pattern and lower uniformity

A Rotary Head will?

Distribute a small amount of water on a large area resulting in a lower precipitation level

Where do you start construction of an irrigation system?

Down stream from the meter

Water pressure comes from?

Elevation, the waters own weight or by means of an electric motor and a pump with blades or impellers.

Tamping

Eliminates any slumping of trenches and the necessity of having the contractor return to the job site to add soil to a settled trench

Which way of watering a shrub is the least expensive and needs the least amount of maintenance?

Emitters

Specific to a drip system three components would be...?

Emitters, micro tubing, pressure regulator

What type of jobs require low voltage irrigation wire to be run in plastic pipe for protection of wire?

Federal Government

Instead of water pressure referred to as PSI, mechanical engineers refer to it as?

Feet head

Which fitting is useful when you have a threaded galvanized pipe and want to switch to PVC Pipe?

Female Adaptor

The terms: friction loss, velocity, surge pressure are considered what?

Flow characateristics

Which valve will develop leaks more than others?

Gate

The automatic command from the controller is:

Given to the valve by either by and electric impasse or by water pressure. If valve are opened by an electric impulse you have an electric system, if opened by a little tube of water under pressure you have an hydraulic system.

The ___ Valve is generally used when all of the irrigation pipe... that is your main and lateral lines... is placed at the same depth?

Globe

There are two basic types of valves; angle valve and globe valve, which one has more pressure loss?

Globe valve

If using plastic pipe for access to a valve you should place the pipe over the valve from ___ down to the valve?

Ground level

What is the best location for the valve box?

Groundcover beds

When you place the main water line so that it intersects near the center of the heads in each irrigation circuit, this is called the?

H pattern of piping

When trenching for pipe placement next to or near a building, utility lines or other plants, what do you use to trench?

Hand tools

What are pipe friction loss charts based on?

Hazen and Williams forumula

When sizing pipe for irrigation why is the largest pipe sized needed not used throughout the entire project?

High costs

How would you install lateral pipe on a slope to avoid major pressure variations and control erosion?

Horizontally

When water from the mainline travels down hill to the valve it?

Increases pressure

The rate in inches per hour that water moves into the soil is called _____ .

Infiltration rate

When laying pipe in symmetrically circuits what can this reduce?

Installation cost

High Hazard Condition

Is Where the water in the irrigation system is toxic and could cause illness or death to people.

Fertigation

Is the injection of fertilizers, soil amendments, and other water-soluble products into an irrigation system.

Low Hazard Condition

Is where you have cross connection but the water in the irrigation system is not hazardous to human health

Evapotranspiration

It accounts for the movement of water within a plant and the subsequent loss of water as vapor through stomata in its leaves.

Bonnet

It acts as a cover on the valve body. It is commonly semi-permanently screwed into the valve body or bolted onto it. During manufacture of the valve, the internal parts are put into the body and then it is attached to hold everything together inside.

Emitters

It acts as the sprinkler head in the drip method of watering. Water is sent under pressure through a plastic polyethylene pipe or tube, and the emitter delivers the water in a precise amount each hour.

Pressure-Rated-Pipe

It is a type of PVC pipe and is produced according to the uniform water pressure for each class of pipe, regardless of pipe size, and is used for pressure mainlines and lateral lines in irrigation projects.

Schedule Rated Pipe

It is a type of PVC pipe and is used primarily under walls and drives as a sleeve to protect more thinly walled pipe.

Drip Irrigation is:

It is defined as the slow application of water to the root zone of a plant by means of a very small sprinkler head called an emitter. The emitter delivers water very slowly, drop by drop, to the soil. It has proven record for watering trees, shrubs, ground cover, flowers, and vegetable gardens. It can also be used for small turf areas.

When routing pipe for irrigation, you should never place pipe at a right angle to the tree roots because?

It may damage or kill the tree

Once the trenches are dug for pipe placement, what must be done before placing pipe?

It must be leveled and smoothed out

Wires for valves buried directly in the ground can attract what?

Lightening strikes

Which fitting has the thread on the outside?

Male Adaptor

Which fitting is used to attach a sprinkler body to a PVC pipe?

Male Adaptor

Emitter placement

Most designers like to run their drip tubing along the path where their emitters are to be located. This way you can attach an emitter and let it drip. If your drip tube is too far from an emitter location, you have to connect micro tubing, or "spaghetti tubing" to the emitter and run it to where you want the drip. If you can run your drip tube to the plant root zones and eliminate the need for microtubing, you can greatly reduce your costs.

Drip Tube Placement

Most drip tubing is black and inconspicuous and can either be placed directly on top of a mulch bed or buried. The tubing is composed of polyethylene, carbon, and ultraviolet stabilizers, which help to resist the destructive effect the sun has on plastic (and especially PVC) pipe.

Dynamic water pressure is what?

Moving water through pipes

When an electrically actuated valve is in its normal state, what does that mean?

Normally closed, no water flow

Pressure Compensating Emitters

Not all emitters can maintain the same discharge rate if the pressure of the water changes. Those that can are termed pressure compensating emitters. They are more expensive than noncompensating types.

Impact Drive Heads

One of 2 types of rotary sprinkler heads. As the pressurized water flows from the head it bumps a spring-loaded arm that slowly moves the head around in a circle. The repeating bumping of the arm makes this a somewhat noisy from of irrigation

Gear Drive Heads

One of 2 types of rotary sprinkler heads. The head contains a number of gears that are turned by the water as it leaves the sprinkler. The movement of these internal gears is what causes the head to turn

Rotary Heads

One of two types of sprinkler heads. Rotary heads are more in a circle and propel water in tiny streams under pressure. Rotary heads can distribute water much further than spray heads can

Spray Head

One of two types of sprinkler heads. Spray heads are stationary and made of two parts, the sprinkler body and the spray nozzle. The Nozzles control the amount of water that leaves the spray head as well as the spray pattern.

Most hydraulically actuated valves when in a normal state are considered?

Open valves

What can cause water hammer?

Opening and closing of valve too fast

Precipitation Rate Formula

PR = Total GPM of an area X 96.3/ Square footage of the area

A spray nozzle will determine what?

Pattern and amount of water coming out of the head

When locating the valve on a system, what is good practice?

Place near center of circuit to allow equal pressure

Most irrigation systems are divided into zones. A zone is a single irrigation valve and one or a group of drippers or sprinklers that are connected by pipes or tubes. Irrigation systems are divided into zones because there is usually not enough ____ and available flow to run sprinklers for an entire yard or sports field at once.

Pressure

Surge pressure

Pressure caused by water stopping suddenly in a pipe, also known as water hammer. Valves must be opened and closed slowly.

Calculating Working Water Pressure

Pressure varies, depending upon whether the water is static (still) or dynamic (moving). Pressure is also affected by the influence of gravity if water drops or rises from one level to another. Pressure will change as it is released downstream through valves along its route of flow and response to roughness inside irrigation pipes.

AMPS and GPM both refer to?

Quantity of flow

What do you use to blow out a system?

Quick coupler valve

What are the basic spacing configurations?

Rectangular, triangular and square

What type of head is best for watering medians, narrow areas?

Rectilinear

The type of wire used for irrigation systems is UF, and the control wire is typically what color?

Red

When using less heads to cover the same area, what does this do?

Reduces costs

What is the last thing installed before the sprinkler head?

Riser

What kind of gardens would you use bubbler heads on?

Rose

In terms of square feet it is less costly to irrigate with what type of head?

Rotary because it covers more area with less heads

If you had a strip that is less than 10 feet wide, what would the best choice of nozzle be?

Rotary multiple stream nozzle

When water passed through pipe what is a cause of pressure loss?

Roughness inside the pipe

When installing conduit, what type of sleeve should be used to run the electrical wire a minimum of 18" underground for landscaping?

Schedule 40

How would you resolve slope problems to some extent?

Setting the heads on the slope at an angle 1/2 way between the vertical and perpendicular to the grade

What does an un-balanced loop design do?

Shorter run, more GPM

Micro Spray Heads

Similar to the spray-heads, but with a discharge rate more like that of an emitter in (GPH). The diameter of water throw is considerably reduced. It is used for small specialized areas of the landscape such as flower beds and groundcover plantings.

What is the device called that acts like a magnet and lifts a plunger that allows water to flow through the valve?

Solenoid

What is the single most important aspect of an efficient water conserving irrigation system?

Sprinkler head selection and placement

The water pressure supplied from the municipal source is 60 PSI. From the main line, a pipe drops 15 feet to the valve that controls the flow of irrigation water. What will be the static pressure at the valve?

Static Pressure at Valve = Static Pressure at Main Line + Elevation Change X 0.433 PSI = 60 PSI + 15(0.433 PSI) = 60 PSI + 6.50 = 66.5 PSI

Moving Water Pressure =

Static pressure in the main line; - the pressure loss in the water meter, the friction loss in the pipe, the pressure loss in valves and fitting; +/- elevation pressure gains.

What is it called when the water level is lower than the pump impeller eye?

Suction lift

Irrigation

Supplying of water to land through artificial means

Water Window

The amount of time available for irrigation.

Discharge Rate

The amount of water flowing from the irrigation system over a measured period of time. Sprinkler systems are measured and rated in gallons per minute (GPM). Trickle systems are slower and measured in gallons per hour (GPH).

Precipitation Rate

The amount of water placed over a landscape area. It is measured in inches of water per hour

Emitter

The device that functions as a sprinkler head for trickle irrigation

Pressure Regulator

The function of a pressure regulator is to reduce the water pressure to the psi relative to the emitters you select.

Friction Loss

The loss of pressure during water flow that results from the increasing speed of the water, the increasing length of the pipe , and the roughness of the lining of the pipe.

What is shutoff head?

The maximum head the pump will produce at a zero flow rate

What affects the rate of absorption?

The more clay, slower the absorption. The more sands, faster the absorption

Flow

The movement of water through the irrigation system

Polyethylene Pipe (PE)

The pipe is black, flexible plastic pipe that is used in irrigation systems, primarily for lateral lines. It was produced before PVC pipe and was one of the first plastic pipes used for irrigation. More durable to sun and winter effects than PVC pipes.

Sizing Irrigation Pipe

The pipe is one of the most expensive factors in the price of an irrigation system. The larger the pipe diameter, the more costly it will be. They will be larger in diameter near the water source and smaller as they are needed away from the water source.

Riser

The piping that connects an irrigation head to the lateral line

Dynamic Pressure

The pressure (in PSI) that is present at any one point in a system as a given quantity of water flows past that point. Dynamic water pressure varies within an irrigation system due to the rise and fall of water as the pipes move up and down across a landscape. Friction losses within the pipes also affect dynamic pressure.

Static Pressure

The pressure (in PSI) that is present in a closed system, when water is not flowing.

Calculating Static Water Pressure

The pressure at the main line source must be adjusted by the pressure created by any elevation change that exists between the main line and the valve. This is done by: Static Pressure at Valve = Static Pressure at Main Line + Elevation change X 0.433 PSI

What is vapor pressure?

The pressure at which water turns to vapor

What is velocity?

The rate at which water is moving and is express in feet (meters) per second. The maximum recommended velocity of water traveling through a pipe for irrigation is 5 ft (1.52 m) per second.

Velocity

The rate of flow, as expressed in feet of movement per second. For landscape irrigation, the ideal velocity of water is 5 feet per second.

In irrigation design, the term hydraulics refers to?

The study of the behavior of water

Pressure is what forces water to flow through pipes to the sprinkler, what creates this type of water pressure?

The waters own weight

Vertical Turbine Pump

These pumps are used in both shallow and deep wells. A motor is installed above ground on a concrete platform, and the pump is placed underground in the water. It can be used in wells over 1,000 ft deep.

What can Spray heads do?

They are generally pop-up types that are recessed below mower level when not in use. Nozzles may distribute water in a full circle, half circle, or quarter circle. They can also deliver water at standard volumes or lower gallonages. They can propel water outward to a distance of only 14 to 16 feet without the pattern being interrupted.

Horizontal Centrifugal Pump

They are less costly and less efficient than vertical turbine pumps. They have to be primed to work, so they are generally placed below the water source, unless you are willing to pay the extra cost for a self-priming unit. They can be used in shallow wells where the pump to the water source is less than 20 ft.

Quick couplers

They are locations where hoses can be connected to the irrigation system to supply supplemental water.

What can Rotary Heads do?

They have moving parts and they may or may not pop up. They all move in full or partial circles and propel water further than spray heads, but not as quickly. They can throw water 110 feet or more from the nozzle.

Pressure-Compensating Emitters

They will deliver the same gap output over a wide range of pressure. They are 2 to 3 times more expensive than non-pressure emitters but have shown they are worthy of the investment.

A controller is a technical name for what?

Time clock

The function of a valve is to:

To let the water flow into a circuit or zone, either automatically on command from the controller or manually.

Why should you use the loop method or loop pipe with irrigation piping?

To reduce friction loss

The controllers function in an irrigation system is?

To schedule the time of day the system turns on and off

The angle that the water leaves the head is known as?

Trajectory

On top of most valves there is a bleed screw, what is the purpose of the screw?

Turns valve on and off

What type of wire is used in low voltage irrigation systems?

UF

When running wire for irrigation in a trench, you should run the wires?

Under the pipe in the trench

Irrigation Pipe

Used for sprinkler irrigation systems, there are two types of pipe currently popular due to their superiority over metal pipe. Polyethylene pipe (PE) and Polyvinyl Chloride pipe (PVC) are widely used both separately and together.

Drip Tubing

Used for trickle irrigation systems, the thin black rubber carries the water to emitters. It is usually black in color and made of plastic.

A device that turns water on or off is called a?

Valve

When determining head placement, the major consideration is?

Water distribution as if it was raining

What causes the risers to pop up on pop up sprinkler heads?

Water pressure

What causes turbulence and shock waves in pipe?

Water velocity over 5 FPS

When would you need to install a pressure regulating valve?

When the system static pressure is above 75 PSI with little elevation change

Static water pressure is calculated when?

When water is standing still

The type of wire used for irrigation systems is UF and the common or ground wires are usually what color?

White or Black

How is operating pressure measured?

With flow in the line

When you want to change from a large pipe to a small pipe you should use?

a reducing bushing

Sprinkler Irrigation

applies water under pressure through a delivery system that delivers the water over the top of plants

Irrigation pipes and valves are usually covered ___ with a valve cover?

at ground level

Sprinkler valve boxes should be located ____ as not to create a hazard once landscape has been installed?

at ground level

An angle valve is best used when what occurs?

changes in elevation

When is a trickle irrigation system useful?

in any situation where slow water application is preferable to sprinkler irrigation due to constraint of space, budget or limited water supply.

Cross Connection

is any connection between the irrigation system and the potable water supply. When you have a cross connection, you have the potential for back flow.

What is the difference between Pressure Compensating and Non Compensating Emitters?

is based upon their ability or inability to deliver a constant GPH over a wide range of water pressures. In landscapes with rolling topographies, the rise and fall of the land causes drastic inconsistency in the water pressure in the thin tubes.

Trajectory

is the path of the water as it is propelled through the air. Flat or low trajectories are used in ground cover and beneath shrubs in in planting beds. Higher trajectories are used for lawns and for plantings that are watered from overhead.

In a static pressure situation, what position is the valve from the mainline in?

off

Precipitation rate

refers to the number of inches (millimeters) of water that is placed over a certain area per hour.

Trickle Irrigation

supplies water directly to the root zone of the plants. The delivery system is low pressure and may be placed on top or within the soil

Sprinkler Head

the device through which water leaves the pipe and is propelled onto the lawns or plantings.

Downstream

the direction of the water flow away from the water source. Pipe that is upstream will be of wider diameter than pipe that is downstream because it must carry a greater volume of water.

How do you determine the number of Emitters needed for a plant?

the soil type and the subsurface wetting pattern that it promotes, the canopy area of the plant, and the percentage of the plant's root zone that is to be wetted. Most plants only require 50% of the root zone to be wetted. Emitters need to avoid direct contact with the trunk or stem of a plant.

Spray Pattern

the specific distribution pattern of a specific sprinkler head

What controls the area that is covered by the Sprinkler?

type of sprinkler head, either circular or rectangular. The size of the sprinkler head and the trajectory of the spray are responsible for the area that is covered

Positioning of Sprinklers

usually set up in a square or triangular pattern. Triangular are preferred because they give more even water distribution and waste less water. Each sprinkler delivers the full amount of water to only 2/3 of its diameter.