General Info TCEQ

Which has the highest precipation rate

spray heads

Which head spacing would provide the highest precipitation rate for any given property

Triangular head spacing

Precipitation rates from most spray heads

exceeds the infiltration rate in most tight soils

Which soil type would hold the most water

clay

Which of the following would affect the precipitation rate of a rotary head

erratic head spacing, nozzle size, head pressure

With most rotary heads, if you adjust the arc down (for instance, from 360 degrees to 180 degrees), the precipitation rate _____

increases

With most rotary heads, if you adjust the arc down, the discharge rate

remains the same

Rotary heads precipitate water more rapidly than any other types of heads

false

Irrigation heads should be selected

to apply water equal to or slightly below the infiltration rate of the soil

Frequent water will result in

A shallow root system

Which is not ideal for dissolving surface fertilizer

Subsurface drip

What is essential to prevent emitters from clogging

filters

Why is ti never acceptable to run drip lines and spray heads on the same zone valve

Because their precipitation rates vary

The licensed irrigator should base his/her design on

Average nighttime wind speeds

Which piping of a sprinkler system will be under constant pressure

main line

A gate valve will have

less pressure loss than a glove valve of equal size

Schedule 40 fittings can be solvent welded to

schedule 40 pipe, schedule 80 pipe and class pipe

Potable water

Suitable for human consumption

Which of the following statements about the “C” value is correct? (how smooth the inside is)

The lower thew “C” value the greater the “C” value

The main design factor that affects the effectiveness of a sprinkler system is ____

precipitation rate

Conventional spray heads discharge a spray pattern that is usually _____ in shape

circular

Which would be affected most adversely by wind?

Stretched head spacing

A well designed rotary system can be just as efficient as a well designed system with spray heads

True

Which of the following is resistant to UV light

Polyethylene tubing

Electric valves are classified as ______

normally closed

The wire to a valve should be pulled fairly tight to prevent the wire from moving in the ditch

False

Which wire is larger?

12 gauge (the larger the number, the smaller the tube, VICE VERSA)

Multi-conductor wire such as 18/6 has

5 circuit wires and 1 common

Master valves are used to prevent velocities above 7ft/sec

False

Any connection made to a potable water supply

cross connection

Water has higher infiltration rates in

Course, sandy soils

The best measure of the amount of water that needs to be replaced by the irrigation system is

Evapotranspiration rate

The basic reason of the amount of water that needs to be replaced by the irrigation system is

Soil moisture content can be kept at a relative constant and proper level

The reason why drip is considered very water efficient and conserves water is

Precise water placement and control, less water lost to wind and evaporation

Which situation would cause the greatest evaporation

Long run times

What type of emission device is used water confined areas (like tree wells)

Bubblers

Shrub heads on risers

Can be a hazard and should be placed against a wall or structure

Excessive water pressure for a sprinkler system

Is a major cause a water waste, will cause water pattern to blow apart. can shorten the life of the head

Never place rotary and spray heads on the same circuit because

Precipitation rates vary greatly

as the wall thickens of PVC ppe increases, the inside diameter

decreases

As the wall increases, the outside diameter

stays the same

In the case of 1” pipe is, the 1” is

The nominal size (just a name)

Corrosion caused when two dissimilar metals come in contact with each other

Electrolysis

Which is not a designated type of copper tubing

“S” (M(thin), L, K (thick))

Which of the following would have the smallest inside diameter

1” type “K” copper

If the proposed pipe size for your irrigation system is 1” then the sleeves for this pipe needs to be at least

1 1/2” (two sizes larger)

PVC 2210 has a design burst strength of:

1000 psi (last 10×100)

Class 315

has a working pressure rating of 315 psi

A safe critical velocity for the water in PVC pipe is

5 ft/s

Oversizing piping results in

more expense

Looping a main supply line in a sprinkler system can

Lower pressure loss to the circuits, and allow you to use smaller pipe for the main supply line

The main factor used to determine how to size down lateral line piping is ____

Velocity

If a system”s head spacing is 15’ then its row spacing should be ____ for triangular spacing

13’ (15 x .866)

What will happen if a gear driven rotary head is installed at an angle?

The spray pattern will be distorted and it will have a poor distribution of water

What happens if the rotation of a rotary head is too fast?

The radius will decrease

Changing out the size of the nozzle on a rtoary head will also change

GPM of the head and radius of throw

An increase in head pressure will

increase flow rate

When is a door not a door?

when its ajar

As the average wind speed increase,

The head spacing should be decreased

If you double the flow of water through your piping, the pressure loss will be

4 times greater

Where is the precipitation rate of a spray head the greatest?

closes to the head

The weight of a 1’ tall column of water consisting of 12 cubic inches is

0.433 lbs

Use diagram to answer 63-66

what is the static pressure at point 1?

53.5 psi-54.5 psi

What is the static pressure at point 2?

66.8 psi-67.5 psi

What is the static pressure at point 3?

53.5 psi-54.5 psi

What is the static pressure at point 4?

43 psi-45 psi