The headings on the manufacturers pages clearly state that the double check
valve is not intended for health hazard applications. I would consider water
from the lawn being in my water lines a health hazard. I agree that it looks
like the check valve would be better than nothing but is not the best
reasonably available protection. I feel sure that codes require the siphon
breaker and, despite many peoples opinions, have valid reasons for doing so.
Codes are for protection against obvious and non-obvious hazards and
compliance is always a good idea, whether there is enforcement or not. Kinda
like stopping for traffic signals when no policeman is in sight

Just my opinion, others will disagree, and it's your decision.
Don Young
"ashroyer" wrote in message
...

Can I use a continuous pressure double check valve when connecting my
sprinkler system to my water line, such as this???

http://www.watts.com/pdf/ES-9DM3_M2.pdf

I've been recommended an Anti-siphon pressure vacuum breaker, such as:

http://www.watts.com/pdf/ES-800M4QT.pdf

But they are more expensive and much bigger.

There are no city codes in my area requiring the use of a backflow
prevention device though I'd still like to put something in.

Andy


--
ashroyer