Irrigation Flashcards
Half circle represents
Arc
Degrees represents
Trajectory
gpm represents
Flow
Feet represents
Radius
psi represents
Pressure
What is a check valve at the base of the sprinkler for
Top stop low end seep
What is the best sprinkler placement in a turf area
Head to head
Which sprinkler is harder to maintain
Rotors
What sprinkler has both radius and arc adjustments in the cap
Rotors
What sprinkler is the most inexpensive
Spray
What sprinkler needs a filter before the nozzle
Spray
What sprinkler has wiper seal that cleans the post as the sprinkler goes up
Spray
What sprinkler have lower PR
Rotors
What are three common manual valves
Gate, Ball and Butterfly
What is the formula for precipitation rate for square placement
PR=96.3gpm/(SL)
What is the formula for precipitation rate for triangle placement
PR= 96.3gpm/((S(L*.866))
What is the formula for precipitation rate for circles square spacing
PR= 96.3gpm/SL * 360/arc
What system, used in agriculture, uses aluminum pipe
Agricultural spray heads
What system uses mini spray heads
Micro irrigation systems
What system is the hardest to troubleshoot
VIH Systems
What BFPD is attached to the hose bib
HCVB
What system allows for individual head control
VIH System
What BFPD has 2 staggering check valves
Double check
What BFPD has reduced pressure between 2 check valves
RPVB
What BFPD has to be installed above the highest sprinkler
AVB, PVB
What is added to sprinklers that are used for sports fields
A rubber cap
A PVC pipe with an SDR rating of 21 has thicker wall than PVC pipe with an SDR rating of 11
No
When would driptubing be the most effective form of micro-irrigation
For a row of young trees, all the same species, in a nursery
What could be done to fix a problem where all the sprinklers in one zone are misting
Add a pressure regulator
In which area of an irrigation system will a pressure regulator provide the most consistency
PRS Sprinklers
What does the C on the terminal strip of a controller mean
Attach the common wire here
The filter that will take silt and clay out of the water is called
Sand separator
The maximum operating pressure of a PVC 1” 1120 Class 315 SDR 26 is
315psi
What is the best type of irrigation device to use in a small perennial bed with plant material of different water requirements
Point source emitters
Which filters are self-flushing
Disk and Sand media filter
In a design how would you correct the problem of too much pressure loss in a zone to run a system
Increase the pipe size
What is the problem associated with electric irrigation valve that will not shut off
A solenoid plunger that is stuck open
How is pressure relieved off the upper chamber in a electric control valve
Through the bypass port
Transformers in residential controllers transform power from 120v to
24 volts
These parts: bonnet, plunger, diaphragm, spring are found in
An electric control valve
According to the CNLA landscape standard what gauge of wires is used for light commercial residential irrigation systems
12 - 18 gauge
When selecting pipe for irrigation what is used to determine the size of pipe
Flow and velocity
Extra components that can be added to a micro irrigation zone are
Filters and pressure regulation
What is infiltration
The rate at which water enters the soil profile. Usually described in inches/hour or mm/hour
What is percolation
The process of water moving through the soil profile
Does water percolate more vertically in sand or clay soil
Sand
In a clay soil would you choose a drip system with emitters closer together or further apart compared to a sand soil?
Further apart. Closer together for clay soils
What is ET
Evapotranspiration
Where is water available to the plant, and between what storage terms
In soil pores between field capacity and permanent wilting point
What is Plant Available Water
The amount of water available to the plant
What is MAD and what is the default %
Management Allowable Depletion, 50%
What is the MAD % for potatoes and tomatoes
40%
How do you determine how long to set your controller in any single day?
RT = (ETl (Plant water requirement) x 60)/ PR (Percolation rate)
How are catch cans placed for an audit
A grid pattern
How long do you run an audit of spray heads and rotor heads
3-6mins for spray heads and 10-15mins for rotors
How do you calculate distribution uniformity?
Du= average of lower quarter/average of total volume
What is a good reading on a solenoid?
Between 20-60 Ohm
When blowing out a residential system with a source psi of 50 what should the compressor be set at?
80psi
What pump needs to be primed
Centrifugal
What type of pump is often used in shallow water
Submersible
What type pump has a motor underwater
Vertical turbine
What is a VFD used for
Allows pumps to be ramped down and ran at frequency and voltage that meets the requirements of motors load
What type of pump is installed in a wet well because the line shaft has to be vertical?
Vertical Turbine
What is the ideal way to layout sprinklers in an irrigation design?
Head to head
What is the constant for TDH calculations
2.31 ft/psi
TDH stands for
Total Dynamic Head
What is multiplied by 2.31 in TDH calculations
Friction Loss and Sprinkler psi
If the sprinklers are below the pump station do you add or subtract elevation and why
Subtract, because you gain pressure travelling down hill.
What is part of a spring startup
Adjust sprinklers Pressure check BFPDPlug in controller Charge battery in controller
What would indicate a pipe was broken?
Wet spots/puddles, low pressure, heads not coming up.
What causes a pipe to break?
Frost cracking, freezing. Shovels. Very high pressures.
What are the 3 groups of problems that can occur in an irrigation system?
Mechanical, electrical, hydraulic.
When dealing with electrical problems, What 3 areas should be checked?
Controllers, valves - solenoid, Field wires.
When checking the controller where should you set your voltmeter?
VAC - high end
When checking a solenoid where should you set your voltmeter?
OHM - low end
What is a good reading on a solenoid?
Between 20-60 Ohm
What voltage does a controller run off?
30vh
Transforms from what to what?
120vh - 24-30vh
When blowing out a residential system with a source psi of 50 what should the compressor be set at?
80psi
Why is water conservation important in irrigation?
Because water is a precious resource and expensive resource
What ways are the industry working to conserve water?
Technology, education, audits/maintenance, certification, and legislation
What ways are the designers, contractors working to conserve water?
Using and designing with the most efficient technology, no overspray, ensuring head to head coverage and matched precipitation rates.
What happens to a sprinkler system if the inlet port in the valve is plugged
The sprinklers will not shut off
What type of information do you need to calculate the system run time?
Plant water requirements, sprinkler performance, soil water holding
How long should you run the sprinklers when auditing a spray head zone
Until you get water in the catchcan averaging 1 1/2 time the catchcan throat area
