I have an incline with 3 long range sprinklers across the top. The Anti siphon valve is located at the bottom of the hill. Sprinklers run fine. When they turn off, all the water in the lines from up the hill pulses out of the anti siphon valve at the bottom of the hill. I have two other stations that have the same system and none of them perform like this. Ideas? This system is 15 years old and maintained.

The weight of the water creates pressure. If, for instance you were to lose pressure in the house, that water could conceivably be drawn back into your water supply for the home, alon with any contaminates it has picked up. It's doing its job, protecting your family, and all of ours.

I understand what this valve does and is supposed to do. My question is of the 4 stations that I have are all in inclines and exactly the same. Why is only this one station pulsing water out the valve onto the ground after the station goes off. If this is normal, it never did it before. I'm looking for information if this is an issue that I need to fix. There isn't much inside.

WELL, the valve might need to be overhauled, but you need to understand that this is NORMAL operation, simply related to gravity. Perhaps one slope is steeper??

In fact, it is a CODE VIOLATION the way you are installed. Code requires the valve to be located minimum 12" above the highest head on the zone.

It may be a code violation now but apparently 15 years ago it wasn't. These were installed by the builder. Thanks for the response.

Jimmy-o is totally right-on and I can tell you positively absolutely that it WAS a plumbing code rule fifteen years ago in ALL of California and that unless you have check valves after the backflow device (which is what your Rainbird valve is) that draining is "normal."

Here is what Rainbird themselves say:

[www.rainbird.com]

"The valve must be mounted at least 6 inches above the highest sprinkler on the circuit."

The backflow rule that jimmy-o referred to has actually been so even in the 1970's when I was a plumbing contractor in the State of California and also when I taught plumbing code in the 1980's and early 1990's at Butte College (located in Northern California).

Just because something passed inspections doesn't make it legal and most building inspectors are asked to inspect all phases of construction and they simply can't be expected to be "experts" in all areas.

I live in No. California and can tell you for a fact that pressure anti-syphon vacuum breakers were then and now where they must be installed at least 6" (12" with many codes) above the highest point of water in the pipe and sprinklers, bubblers and drip emitters that it serves.

Vic

They all SHOULD do the same thing, which is why the installation instructions say the antisiphon valves MUST be installed at least 6" above the HIGHEST point on the zone.

It was ALWAYS a violation, if not of a code, then of the installation instructions. The ones that are NOT leaking are the ones which need to be repaired, because the discs may be stuck to the valve bodies.

quote; Just because something passed inspections doesn't make it legal

More likely the system was installed AFTER the inspection. It is also not the way most "contractors" install a system. They normally use a single backflow preventer at the connection to the house and they install underground "in line" valves without the individual vacuum breakers

You could simply install a spring check next size up after the atmospheric check valve and should have in Your other noted installs.atmospheric checks are not designed to be relief valves and you should protect against this use.simply over size spring check your problem.. .

quote; atmospheric checks are not designed to be relief valves and you should protect against this use.

IF that is so, then WHAT are they designed to do.

Relief as prescribed is anti siphon////////NOT BACKFLOW\\\\HJ??come on you know.As said code would not. could not allow.as it is an engineered failure to have higher water available to drop above the valve install.It's function creates vacuum and would or could draw back water into it's opening.Same reason flood plains for relief type rpz's should be posted with permits???How many are?Most allow twelve above /installed ground\ inches and conclude function.Where the fix is the poster. An over sized spring check on the outlet will.Disagree HJ?Any code not allow any check after the atmospheric?Any not allow after rpz? Simply, fix the install!

quote; Relief as prescribed is anti siphon////////NOT BACKFLOW\

C'mon Lemon. You SHOULD know that is a combination anti-siphon AND backflow preventer, since EITHER Condition could cause contamination.

Disagree /by code /but understand/failure.Can you Rain Bird me some facts.I own several cloth parallel.Funny why They sent it to me.You to can receive?Ask the question/questions. FIS southern region