# Do I need to raise my irrigation valve(s)?



## downunder (Jun 13, 2008)

All of the systems I have worked on have the solenoid valves in a valve box in the ground (somewhat like a meter box) and the irrigation heads are risers which sit flush with the ground and rise when activated. So in theory all should have water hammer since the valves are all below the level of the heads. Not so. I did use a cheap battery operated controller on an outdoor faucet one time that caused a little hammer when it cycled, but you have to consider what it was.



> How can I check if the valves are preventing backflow as they should and what can I do to fix the problem if one is found?


They won't because they don't. These are two different things. The valves simply turn the water on and off. An anti-syphon/anti-backflow preventer is a completely different device.

But, getting back to the water hammer. Maybe installing a water-hammer preventer between the house and the irrigation system would work. You can get small ones that go on individual fixtures as well as larger ones.


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## MrSmythe (Aug 23, 2010)

> All of the systems I have worked on have the solenoid valves in a valve box in the ground (somewhat like a meter box) and the irrigation heads are risers which sit flush with the ground and rise when activated. So in theory all should have water hammer since the valves are all below the level of the heads. Not so. I did use a cheap battery operated controller on an outdoor faucet one time that caused a little hammer when it cycled, but you have to consider what it was.


I may not have been very clear in my first post. I know the water hammer isn't because of the level of the valves or the risers, but because of the abrupt stoppage of flow that occurs when a valve closes. I recognize that the backflow issue and the waterhammer issue are two separate issues. 



> But, getting back to the water hammer. Maybe installing a water-hammer preventer between the house and the irrigation system would work. You can get small ones that go on individual fixtures as well as larger ones.


Can I install it on the PVC line just before it connects to my sprinkler valves? What kind should I get for that? The ones at HD either look like they need to be soldered or are specifically for washing machines.


This "rainbird 075-ASVF" looks like what I have:

http://www.westsidewholesale.com/3-...trol.html?cm_mmc=amazonproduct-_-na-_-na-_-na

It says it has an atmospheric backflow preventer. It also says that it is supposed to be installed 6 inches above the highest head on the line. So does this mean that I have to raise the thing up nearly 2 feet into the air because of the height of my flowerbed? These valves are right up against the rear wall of the house so this will look kind of odd..is there another solution?

How can I tell if the valve is preventing backflow or not?


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## downunder (Jun 13, 2008)

Sorry,
I'm not clear on what issue you need help with. I don't have any experience with the Rainbird valve you mentioned so I can't comment on that. Actually, I've never had a problem with water hammer on irrigation systems. There are plumbing adapter fittings that will change from PVC to copper so I'm sure you could find something to accomplish that if need be. As far as backflow preventers on irrigation systems, I don't particularly subscribe to that thinking and I"ll leave it at that.


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