3
Types of Zone Valves
There are two basic types of zone valves commonly available.
Anti-Siphon Valves
Anti-siphon valves have a built-in backflow device to prevent
possibly contaminated water from flowing backward into the
household supply. If approved by your local codes, these types
of valves provide inexpensive backflow protection. Anti-siphon
valves must be installed at least 6" above the highest sprinkler
head on the line in order for the backflow device to work
properly. Both automatic and manual versions are available.
Anti-siphon valves are an inexpensive choice and easy to install and maintain. The built-in anti-
siphon backflow device prevents potential contamination of household water supplies from fertiliz-
ers and other toxic chemicals which may enter the system.
Check your local codes for the types of backflow protection required in your area. Electric models
are simple to hook up to a controller for automatic watering. They are best suited to plans where
there is not more than a slight rise in elevation, and fairly clean source water.
Caution:
This valve is designed as a zone valve and as such may not
function properly, resulting in water contamination, if installed where
constant pressure is placed on the outlet (sprinkler) side of the valve. The manual version
is not
suitable for use in a continuous open position as a main shutoff valve or as a means of inexpen-
sive backflow prevention for an entire system; nor are the automatic models to be used as a mas-
ter valve where other valves will be installed downstream.
Must be
at least
6” above
the
highest
sprinkler
Installation Notes
Must be installed upright
Must be installed at least 6"
(15,2 cm) above the highest
point of water in the pipe
and sprinklers it serves
No valve can be located
downstream of the anti-
siphon valve
Must not be subjected to
operating pressure for more
than twelve (12) hours in
any twenty-four (24) hour
period
Uniform Plumbing Code
Sec. 1003 (2) 602.2 Con-
sult local codes
