I’m wondering about the air inlet valves that are on freeze-proof faucets. They appear to allow air into the faucet stem when the valve closes and pressure is off.
Are these items available separately? I’ve got a typical Orbit 24V irrigation valve that regulates water to our garden/orchard which is a good 75 vertical feet below the building where the valve is. When the valve closes it appears to take a terrible beatin’ caused by the “pull” of all that water below. I can hear the valve diaphragm slamming shut, then fluttering and banging as the mass of the downhill water decelerates. Eventually it closes and stops the water, but it doesn’t seem to enjoy the process. I have had to replace the valve once due to this abuse.
I’m thinking that if relief air could be introduced on the down-side of the valve, it would be happier. Thoughts?
Thanks,
Scott.
Edited 7/20/2009 8:43 pm by Scott
Replies
Yes there are vacuum breakers that screw onto the threads. Only trouble is the hose will empty completely each time the bib is shut .
Rich
>>>Only trouble is the hose will empty completely each time the bib is shut .Don't know why that would be "trouble". In my case it's fine because it allows about 200 feet of 3/4" pipe to drain into the garden instead of hanging off that poor little diaphragm.Thanks for explaining,Scott.
It's known as an anti-siphon or vacuum breaker.
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Should do what you want, more or less.
Get a valve with anti-siphon.
Orbit has a number of them in plastic and brass.
http://www.orbitonline.com/search/?searchbox=siph
But you can use any brand.
http://www.irrigationtutorials.com/instal07.htm
http://www.sprinklertalk.com/manuals/rain_bird/das_asvf_manual.pdf
William the Geezer, the sequel to Billy the Kid - Shoe
In fact, I'm surprised that the existing installation lacks a vacuum breaker, since it's been code requirement for irrigation hookups for probably 20 years now.
As I stood before the gates I realized that I never want to be as certain about anything as were the people who built this place. --Rabbi Sheila Peltz, on her visit to Auschwitz
Not exactly.The require back flow prevention.But the anti-siphone is vavle is not allowed to be the back flow in many areas.And separate devices are used where the water supply stubs out for the sprinkler system..
William the Geezer, the sequel to Billy the Kid - Shoe
If nothing else, a vacuum breaker is SOP in northern climes, since it's needed to prevent (or at least reduce) frost damage.
As I stood before the gates I realized that I never want to be as certain about anything as were the people who built this place. --Rabbi Sheila Peltz, on her visit to Auschwitz
>>>I'm surprised that the existing installation lacks a vacuum breakerThat would be because Scott built it. Didn't know.Now that it's explained I can see why it's a good idea....mostly because of backflow issues, although it's not even remotely possible in my situation. Like I said...there's 75+ feet of elevation loss once the water exits the building. So the vacuum break solves a different problem, that of all that mass hanging off the diaphragm of the valve.Thanks All!!!Scott.
Most cities require a better backflow preventer, usually a double check or reduced pressure, and tested annually by a certified person.http://www.irrigationtutorials.com/backflow-preventers.htmthat describes all of the types.And here are some typical ones.http://www.febcoonline.com/Products/850_Small_Diameterhttp://www.febcoonline.com/Products/860_Small_DiameterBut in your case the anti-siphon should be fine..
William the Geezer, the sequel to Billy the Kid - Shoe
Edited 7/21/2009 10:36 am by BillHartmann