Term
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Definition
| manipulating how much water pressure is lost between the point the water enters your yard & the sprinkler head |
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Definition
| Used on meters if pressure is above 65 PSI |
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Definition
| Pressure of water system when water is flowing |
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Definition
| Pressure of water in a system when the water is not in motion |
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Definition
| protects drinking water supply when a valve breaks or leaks or when pressure drops in a water system. Usually mandatory to install one on a system. |
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Term
| Reduced Pressure Backflow Preventer (RP Unit) |
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Definition
Standard for commercial irrigation intallations.
Must be installed 12" above ground, btu not higher than the sprinklers
Installed upstream of all the valves
Units may spit out water if backflow is detected or if they are broken.
-pressure loss: 12 PSI |
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Term
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Definition
| valve used to turn on & off a group of sprinklers or a drip system |
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Term
| atmospheric vacuum breaker (AVB) |
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Definition
- least expensive BFP
- installed on the pipe right after the control valve
- must be installed after every control valve
- must be installed at least 6" higher than the highest sprinkler head, bubbler or drip emitter outlet that is turned on/off by that control valve
- not economical if you have more than 6 valves
- pressure loss: 2 PSI |
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Term
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Definition
manual or automatic control valve with a built in atmospheric vacuum breaker
- must be installed 6" higher than the highest sprinkler head or drip emitter outlet
the anti-siphon valve will not work if any valve is installed downstream
- downstream valve creates 'back pressure' on the anti-siphon valve which causes the vent in it to jam in the closed position.
- if vent can't open, backflow will not be prevented
- most common type of backflow preventer used on residential irrigation systems |
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Term
| pressure vacuum breaker (PVB) |
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Definition
- only 1 needs to be installed on the mainline leading to the control valves
- must be installed 6" above the highest sprinkler head or drip emitter controlled by any of the valves
- needs to be installed at the highest point in the yard with mainline running to it from the water source and another main running down to the control valves
- may spit water out when backflow occurs
- installation of a spring loaded check valve may stop or reduce water spillage
- pressure loss: 5 PSI |
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Term
| Double Check Backflow Preventer |
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Definition
-always has 2 maunal valves (inlet & outlet)
- 2 spring loaded check valves in a row with a shut off valve on either endand test cocks to allow the unit to be tested for proper operation
- only true backflow preventer that does not have a vent to allow air to enter lines or allow water to escape when backflow occurs
- relies on the tight seal of 2 check valves to prevent backflow
- Can be installed lower than the irrigation system
- may not be used on any irrigation system where chamicals are injected into the irrigation water
- pressure loss: 3 PSI |
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Term
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Definition
| should be installed at the closest point possible to your water source in case you need to work on the system |
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Term
| What type of pipe should be used for irrigation mainlines? |
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Definition
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Term
| What depth should mainlines be installed? |
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Definition
| 18" min. & below the frost level |
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| What class of pipe would you use for an irrigation system with 100 PSI pressure |
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Definition
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Term
| HOw is pressure loss in pipes calculated? |
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Definition
| PSI Loss Value x Length of Pipe / 100 = PSI loss in pipe |
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Definition
available in any size
installed underground
does not incorporate a backflow preventer
most commonly used on commercial systems |
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Term
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Definition
available in only 3/4" & 1" size
recommended for homeowners
incorporates a backflow preventer
must be installed above ground 6" higher than the highest sprinkler head
locate at the highest point in yard |
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Term
| What is the change in pressure of water for every foot of elevaion? |
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Definition
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Term
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Definition
spray a fan-shaped pattern of water
spaced up to 18 feet apart
need between 20-30 PSI water pressure to operate properly |
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Term
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Definition
operate by rotating strams of water back & forth over the landscape
- spacing 18-55 feet apart
- small rotors for residential 25-35 ft. spacing |
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Term
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Definition
pop-up sprinklers - installed below ground
shrub sprinklers - above ground also called risers |
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Definition
operate best at 20 PSI
pressure comensating for large elevation changes |
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Term
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Definition
- used in warmer climates
- 2 systems: C1 (class) & SCH (schedule)
- class pipe - rated by pipe's operating system
- schedule - rated by pipe's wall thickness |
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Term
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Definition
- used in areas with very cold winters
- does not hold up as well under high pressures
- better for rocky soils
- SDR ratios - lower # stronger pipe |
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Term
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Definition
| pipe sections between control valves and sprinkler heads or drip emitters |
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Term
| what is the pressure loss for lateral pipes? |
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Definition
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Definition
| head to head spacing required |
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Term
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Definition
lawns & shrubs never on the same system
shady & sunny areas never on the same zone
plants with different water requirements should not be in same zone
never combine spray heads, rotors or drip in same zone |
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Term
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Definition
pressure loss caused by turbulence
friction loss determined by type of pipe, diameter of pipe, amount of water flowing through pipe & length of pipe |
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Definition
| single valve & all pipes, fittings and sprinkler heads downstream from it |
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Definition
| should not be over 5 ft/sec |
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Term
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Definition
force water to move by displacement
piston pumps, diaphragm pumps, roller-tubes & rotary pumps
used for moving very thick liquids, creating very precise flow volumes or creating very high pressures
not typically used for irrigation systems except for fertilizer injectors |
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Term
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Definition
uses an impeller to spin the water rapidly ina casing, chamber or housing
- spinning action moves water through the pump by means of centrifugal force
- may be multi-stage, more than one impeller & casing
- must have a wet inlet
- must be primed by adding water to pipe before use
- pump cannot suck air |
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Term
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Definition
- installed completely underwater includin motor
- shaped like a long cylinder to fit inside well casing
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Term
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Definition
- centrifugal pump mounted underwater & attached by a shaft to a motor mounted above the water
- very efficient & are used primarily for larger pump applications
- often consist of multiple stages each stage another pump stacked on top of the one below
- typically seen on farms, also for large parks & golf courses when pumping from lakes
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Definition
- used to increase water pressure of water that is already on its way somewhere
- boosts water pressure
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Term
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Definition
submersible pump or turbine pump attached to the bottom of a float
- good for lakes & ponds
- easier to install & more energy efficient than end-suction centrifugal
- floating fountains & pond aerators also use this technology |
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Term
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Definition
| as flow increases, pressure decreases |
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Term
| how is the output of pumps is measured? |
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Definition
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Term
| what is the static pressure of water @ 100' el? |
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Definition
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