1/2 vs 3/4 outdoor frost free sillcock

[Jadnashua]

You at the minimum want a vacuum breaker, either built-in, or add-on. In many places, a backflow preventer is required, and in many places, it must also be tested by a certified tech as often as annually to ensure it is protecting the water supply. Yes, it takes a special set of circumstances to happen, but you can contaminate your home's water supply. One possible scenario is if there's a fire nearby and they are using all of the fire hydrants to maximum flow while your sprinklers are on. You could suck up stuff into the supply lines. It could be something that you do, but more often something that happens in the system. A certified backflow preventer is moderately expensive, but the price many people pay to protect their and their neighbors' water supply.

 

[Jadnashua]

The Woodford Model 27 has both a vacuum breaker and a ASSE 1052 backflow preventer built-in.
http://www.woodfordmfg.com/woodford/Wall_Faucet_Pages/Model-27.html

 

[Sponsor]

 

[Dlarrivee]

Pretty sure the guy at HD even said the same when I asked. I don't think this is a very common topic here in Canada.

So because the guy at HD didn't know what he was talking about, all of Canada doesn't have a clue?

No wonder the Americans think we live in igloos.

 

[mjm]

So because the guy at HD didn't know what he was talking about, all of Canada doesn't have a clue?

No wonder the Americans think we live in igloos.

whoa whoa whoa, that's not what I was insinuating. I'm just saying after searching and talking to about 4 or 5 people about these units, this is the first I heard of backflow concerns. Had I talked to a real plumber first they may have set me straight right from the get go. Or maybe they all assumed I already knew about it. and I do live in an igloo, something wrong with that?

 

[Jadnashua]

Codes differ not only from town to town, but especially from one country to another. Canada's plumbing regs are similar to those in the USA, but by no means identical. Here, most places require a backflow preventer precisely because there have been situations where installations without one has gotten people sick. With that in mind, since there is a valve available with that built-in, and not too expensive...personally, I think it's worth looking into. Not sure if Woodford stuff is readily available there, but they do sell direct on their website - if, they'll deliver to Canada, I don't know.

 

[hj]

IT IS definitely a "back flow preventer" as well as an anti siphon device. The disc that prevents it from leaking is held in place by the incoming pressure. IF that pressure disappears, which it would have to in order to all siphoning OR backflow, the disc seals the "inlet" port and opens the vents around the perimeter. This either interupts a siphoning condition INTO the house, (but, not through the antisiphon device if the siphonng source is above the hose bibb), or prevents back flow.

 

[Jadnashua]

Woodford Model 27 has an approved double-checkvalve as opposed to a conventional vacuum breaker which is why I mentioned that one. It was specifically designed for applications like where you use the hose bib to feed a sprinker system and meet US codes for that application (at least what I read in their specs).

 

[mjm]

IT IS definitely a "back flow preventer" as well as an anti siphon device.

Is this the knob on top, we are talking about here?

btw, I am not questioning this whole thing because I do not want to do it. I'm all for doing things right and above code. This is why I am asking so many questions. I do plan on having the backflow protection one way or another, but I want to know what I am talking about for my next trip to a plumbing supply place.



It's twice the price to ship to canada, but driving around lookiing for one adds up with the price of gas too.

1 question is 3/4 MIP x 1/2 FIP wouldn't that allow the same amount of water through regardless of 3/4 or 1/2 line going into it. Doesn't this unit just put the 3/4 down to a 1/2 flowing through?

 

[Gary Swart]

There seems to be some confusion between the terms "anti-siphon" and "back flow preventer". Gentlemen, the function of this feature to to prevent siphoning. Now certainly, the back flow preventer on an underground sprinkler system is more complex than what is use on a hose bib, but the end result is the same. You don't have to believe me, just go to a hardware or plumbing shop and look at one and read the label on the package. If you ask the clerk for an anti siphon frost free hose bib, or a hose bib that is frost free and has a back flow preventer, you will be directed to exactly the same thing. End of story.

 

[Jadnashua]

There seems to be some confusion between the terms "anti-siphon" and "back flow preventer". Gentlemen, the function of this feature to to prevent siphoning. Now certainly, the back flow preventer on an underground sprinkler system is more complex than what is use on a hose bib, but the end result is the same. You don't have to believe me, just go to a hardware or plumbing shop and look at one and read the label on the package. If you ask the clerk for an anti siphon frost free hose bib, or a hose bib that is frost free and has a back flow preventer, you will be directed to exactly the same thing. End of story.

You may be directed to the same place, but in fact, they are NOT the same. It is the level of the protection that they provide that differs. The Mansfield product I pointed to comes in many forms. Only one of their models (I think, at least in the residential line) has a dual-check valve that is certified for use on a sprinkler system. All of the others have vacuum breakers. Both provide some backflow prevention, but only the dual check valve version is approved for use with a sprinkler system. A nice feature of the Mansfield products is that they also have internal features that will prevent frost damage even if you DO leave a hose connected during freezing temperatures. On some, with just a vacuum breaker, they'll drain when you shut the valve off. On the others, there's an internal check valve that opens if the pressure exceeds 300# - low enough to not damage the valve, but high enough to not regularly open except in that freezing sitution.

 

[mjm]

So I just called a small plumbing company and talked to the guy there, and he said he should be able to get me a 3/4 no problem. Then I explained what I was doing and we talked about the backflow situation. He said what I need, to be up to code is a double check valve assembly.
I am going to show him pictures of what I am working with and he should be able to set me up with everything I need, hopefully.

 

[Jadnashua]

And, the one I pointed you to awhile ago is exactly that...it has a code compliant double checkvalve.

 

[mjm]

And, the one I pointed you to awhile ago is exactly that...it has a code compliant double checkvalve.

Thanks, I thought that might've been a bit of overkill, but now that I know it is code, I guess it's what I need.

 

[Ballvalve]

You would be a lot safer in life without any hose 'protection'. .... by washing your bean sprouts and lettuce twice or having them irratiated at the packing plant.

All this backflow protection on residential hoses is just industry lobbying to give them a new and essentially useless new market.

You have 60 DEAD people in Germany from a bean sprout, but no one is going to start a bean sprout protection industry.

Much ado about nothing. Put in the hose bibs you grew up with as a kid.

Overkill? Yes, but way beyond. Misapplied and a result of overeducated and industry tainted government robots creating jobs for themselves and brass casters.

Check your seatbelts and air bags. Forget your garden hose.

 

[Terry]

We installed a double check valve on a home in Medina, they were blowing out the irrigation system in the yard, and it was forcing the water back into the main and causing problems to the plumbing in the homes nearby. We're talking homes worth millions. They weren't liking it.

So we installed a double check valve on the incoming water. City required after the neigbors complained of the problems.
Being hooked to a city main does not make someone independent.
Maybe on a well, but not on a street with other homes.

Any irrigation system should be on some sort of back flow prevention.
It it's at the high point, you might get by with a vacuum breaker.
Lower then that and they may insist on a double check valve.

 

[Ballvalve]

Irrigation and city water with a chance to go backwards for special reasons make sense, but we all grew up without anything on our garden hoses except a valve and our mouths on a hot day.

And most of those were on city water.

Sort of lke the genius that drains a resevoir because some drunk peed in it. Even though a dead skunk is likely laying on the waters edge.

 

[Terry]

When the city shuts off the mains, everything siphons backwards.
There have been cases when resturants have left a hose into god knows what, and during a water main repair, sucked whatever the hose was placed in and back into the main, to be respread to the neighbors. And people did get sick.

As long as nobody ever shuts off the main, then yes it would be safe. These measures are taken because leaks happen, shutoffs happen and sickness as a result of that happens. It's part of being joined at the hip.

One Winter when my younger brother was living in Preston, He was getting freeze breaks.
There was no shutoff on his home, so we turned off the entire city of Preston to fix his leaks. We did this for several days, finally getting smart, digging up the water service outside and adding a shutoff to his incoming copper line.

 

[LLigetfa]

There was no shutoff on his home, so we turned off the entire city of Preston to fix his leaks.

These days some professional plumbers have liquid CO2 systems to deliberately freeze pipes to shut off the flow in order to effect a repair. I saw it done on Bob Villa.

http://www.dryicesource.com/dryice/fixpipes.php

 

[Terry]

I don't know too many plumbers that have those.
I would use one once in a Blue Moon.

 

[BobL43]

maybe conducted heat through the copper tubing that gets some warmth from the house interior, but you can't depend on that for sure to prevent freezing even with the insulated cover. Got to drain that baby.