(this has been moved by me from another thread here (https://www.askmehelpdesk.com/plumbing/anti-siphon-valve-installation-337480.html#post1718122))


If you have 2 valves in different places at different elevations, is it true that each valve only needs to be higher than the highest sprinkler that it services? I would like to split the supply line and service 2 different areas. Its easier to run electric wire than PVC.
19532



Thanks!

If the anti-siphon valve is lower than sprinkler it will drain water from the sprinkler branch after sprinkler is deactivated. Small overflow will follow from the anti-siphon valve.

You could solve this problem by installing check valve on sprinkler branch that would hold water in disallowing it to push backwards towards the anti-siphon valve.

I agree with Milo to install a check valve and yes it is true that each anti-siphon valve should be higher than the highest sprinkler, Thanks.

John

Thanks for the responses

In my diagram, each valve is higher than the sprinkler it serves. The question is whether sprinkler 1 being higher than valve 2 is an issue, or if valve 1 and 2 serve their backflow-prevention independently.

Here's the deal: I live in cold winter country, but want to keep with the simplicity of anti-siphon valves for backflow prevention. I could run my supply to the highest spot on the land then back to where it goes, which would be a bit of hassle and cost but certainly do-able

The way it is drawn it is perfectly fine... The back-flow prevention is served by each valve independently. No need to do any modification to this design.

Milo I can't rate you it wouldn't let me But I can respond to you this way, you have stated very well no need for me to say any thing.

Pwd77, your drawing is perfect no need for any thing else, good luck.

John