1. 4/1/2011
Irrigation Valves
Valves used either to release water into:
a.distribution lines
b.sprinkler heads
Valves can be:
a.manually opened
b.opened by remote
c.automatic controllers
d.auto shut down with pressure
differentials (pumps)
Opening and closing of remote valves either
the diaphragm type or piston type
• Most used are diaphragm type because less
parts to wear
• Piston types have valves and rings that need
periodic servicing
Electric valves electric diaphragm valve
•24 -Volt valves open and close with solenoid.
• Most electric valves in closed position with
power off
• When 24 volt currant. solenoid draws
plunger in and pressure of water pushes
diaphragm upward
•Power off – pressure holds diaphragm
closed
Note* severed wire valve will be closed
Electric valves either in line or attached to
sprinklers (valve in head)
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2. 4/1/2011
Turf Irrigation Manual By: Richard Choate
http://www.superiorcontrolsco.com/product_main.html
Electric valves either in line or attached to sp
Turf Irrigation Manual By:
Richard Choate
Tips for installing electric valves
1.Install a shut off valve to isolate & make
repairs easier
2.Do not cram valves / shut offs into service
box. (Use the correct size of box)
3.Place valve boxes on gravel base
4.Leave at least 12 inches extra of wire. (do
this for valve in head as well)
5.Use Teflon tape for connections, not pipe
dope
6.Install valves straight for ease of service
7.Use PVC Primer on welds
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3. 4/1/2011
TYPES OF VALVES
1. Globe valves
Turf Irrigation Manual
By: Richard Choate
High resistance to water flow due to small openings and
sharp turns.
2. Gate Valve
• From outside globe and gate valves look similar.
• Gate lifts and lowers as you turn
• To close turn to right to open turn to left
• Fully open straight run and least resistance
Turf Irrigation Manual By:
Richard Choate
3. Ball valves
• Little resistance when fully open
• Works by lever action.
• Place with handle perpendicular to ground for
better leverage
Turf Irrigation Manual By: Richard Choate
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4. 4/1/2011
4.Quick coupler valves
Turf Irrigation Manual By: Richard Choate
5.Check Valves
• Placement with relation to flow extremely
important in installation
• Allow flow only in one direction
• Discharge side of the pump (on centrifugal
pumps)
Check Valves continued:
TWO TYPES
a. Spring loaded that pushed out of
the way for flow and spring closed
do to back pressure.
Turf Irrigation Manual By: Richard Choate
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5. 4/1/2011
Check Valves continued:
b. Wafer Swing Check Valve
Turf Irrigation Manual By: Richard Choate
6.Foot valves
• Important with pumping systems
• Used on non-submersible pumps (i.e. jet pumps)
• Shut down pump foot valve closes and will not let
water drain out of system. It keeps the pump
primed
Turf Irrigation Manual By: Richard Choate
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6. 4/1/2011
7.Atmospheric Vacuum Breakers
•Stops siphon action
•Placed right after supply line shut off valve
•Check valve that will seal when water shut down or
flow reversed. Back flow directed to atmosphere
Turf Irrigation
Manual By: Richard
Choate
•Mandatory when protecting domestic water
•Minimum 6-12” above highest sprinkler
Turf Irrigation Manual By: Richard Choate
8. Air Gap
Turf Irrigation Manual By: Richard Choate
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7. 4/1/2011
9. Backflow prevention valves
Two types of back flow
a. Back siphon – when water travels from
area of high pressure to low pressure.
Example:
Example:
City pressure drops due to high
demand, i.e. fire hydrants turned on.
Backflow prevention valves continued:
b. When elevation or other causes result in a
higher pressure on the irrigation system
than on the supply system.
For Example:
If system is off and there is an elevation
change from the system to the backflow
then there is a back pressure on the
backflow valve. The degree of pressure is
dependent on the elevation
System on
System off
Back Flow
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8. 4/1/2011
Backflow prevention valves continued:
Placed right after source shut off:
i.e. city shut off. > meter > backflow prevention
device
Reasons
•No water back into city water
•Sprinklers are ground level or below, it is
conceivable that ground water could enter
back into sprinklers.
•Often times irrigation systems can be fitted
with fertilizers or pesticide injectors
Backflow prevention valves continued:
• Many types some, or most, for large
irrigation systems
• Often they consist of two spring loaded
valves that are in line.
• When water shuts down flow stops and there
is a “dump” after the first valve that water will
exit in backflow.
• Backflow devices are the law for hose bibs.
(filling spray tanks)!
Backflow prevention valves continued:
Turf Irrigation Manual By: Richard Choate
Spring loaded valves
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9. 4/1/2011
Backflow prevention valves continued:
• Devices more complicated on automatic systems
under constant pressure.
• Backflow devices are the law when connected to
municipalities.
• Used when municipal or city water is used in an
irrigation system
• Water departments will specify device and will test
(at a minimum) annually to assure proper operation.
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