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INSTALLING YOUR SPRINKLER SYSTEM
02/09/12
* The first step in installing the sprinker system is to build a manifold.
A manifold is a group of control valves connected to a length of PVC pipe, spaced
3" to 6" apart. Water comes to the manifold from the supply line,
then is routed through the proper control valve to the circuit by the controller.
The manifold can be mounted above ground or buried (with the control valves
projecting above ground), then covered with a box.
* Next, dig V-shaped trenches at least 8" deep for the pipe. The trenches
should be straight and reasonably level. To tunnel under a sidewalk, connect
a piece of galvanized pipe to a garden hose and turn the water on full force
to wash away the soil. Then cap a length of PVC pipe with duct tape and drive
it through the hole.
* Tap into the water supply line (Figs. 3, 4, 5) by installing a tee at one
of three locations: 1) just past the water meter in the basement; 2) just behind
an outside hose bibb; or 3) along the main supply line before it enters the
house, but past the outside meter (if there is one). Install a stop-and-waste
valve as an emergency shutoff and to be able to drain the system for the winter.
Install the shutoff valve just past the connection to the supply line, then
run pipe to the manifold. Once the PVC connections are cured, turn the water
on for a minute or two to flush the system.
FIG. 3 - Tapping into the water system
at a hose bibb.
FIG. 4 - Tapping into the water system
in the basement, just past the water
meter.
FIG. 5 - Tapping into the water system
outside, just past the water meter.
* Install antisiphon valves onto the control valves to prevent contaminated
water from getting back into your home's supply lines (Fig. 6).
FIG. 6 - Each control valve should be
fitted with an antisiphon valve; the
assembly should be at least 6" from
the ground.
* Lay the pipe in the trenches, then begin making connections. Before you install
each threaded riser tee, screw the riser in place temporarily. As you install
the riser tees, hold a carpenter's square against the riser to make sure the
tee is set so each riser will be at a 90-degree angle to the ground.
Once the pipes are assembled and the connections cured, install the risers
(Fig. 7). Cut them carefully to make sure the sprinkler heads will be at the
correct height. Once the risers are in place, attach the sprinkler heads (Fig.
8).
FIG. 7 - Run the pipes from each
control valve in turn. Be sure to
test the system before you fill the
trenches.
FIG. 8 - A pop-up sprinkler head
(left) and a rotary head (right).
* Finally, mount the controller (typically, the controller goes in the garage)
and run low-voltage wires to the control valves. Set the watering controls for
each circuit, then test the system by opening and shutting each circuit. Backfill
the trenches, then water the soil down thoroughly to compact it. Add more soil
until each trench is slightly raised, then replace the sod or reseed.
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