7
Point of Connection
4. Add the l/min requirements of those two heads together
to size the next pipe.
5. Add the l/min requirements of the next head to the
previous total.
6. Continue to do this until you get to the zone valve. Be
sure not to size a pipe smaller than the chart indicates.
7. Repeat Steps 1 through 6 for each zone.
Main Line
1. Determine the location for the system point of connection.
It should be near the water supply.
2. Draw a line connecting all the manifolds together, and
then draw a line connecting this line to the P.O.C.
3. The main line should be one pipe size larger than the
largest lateral line.
G. Point Of Connection (P.O.C.)
Connecting to City Water Supply
Use a brass compression tee to hook your sprinkler system to the
household water supply line. You may hook up to copper, PVC or
galvanized iron service lines without having to solder or thread
any pipe.
Most areas require some type of backflow preventer to protect
drinking water. Copper pipe may be required between the P.O.C.
and the backflow preventer. Always check the local building code
or with the local permitting agency for the requirements in your
area.
Connecting to City Water Supply in Freezing Climates
If the installation is in a freezing climate and the P.O.C. is in the
basement, install a drain valve immediately after the isolation
valve to drain the irrigation line before first freeze.
Connecting to a Pump
When the water source is a tank, lake, well or bore hole the
irrigation system is usually pressurized by a pump. A foot valve
may be installed at the inlet of the suction line to keep the pump
primed. A check valve should be installed on the discharge line
to prevent backflow. A manual control valve should be installed in
the discharge line to regulate flow and a pressure gauge should
be used to monitor dynamic system pressure. Try to minimize
elbows, bends and other causes of turbulence and friction in the
suction and discharge lines.
Review Design
The design process is now complete. Check to make sure you
have placed sprinklers in all areas. Also, review the pipe layout to
be sure you have sized the pipe correctly. You are now ready to
begin installing the system.
P.O.C. to city water supply: Use a brass compression tee
to connect your sprinkler system to the household water
supply.
P.O.C. freezing climate
TIPS
Most professional installers recommend PVC pipe
for the constant pressure line from the backflow
preventer to the zone control valves. Some
communities require copper, however. Check
local ordinances before laying out your system.
