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silvercvic
10-25-2006, 02:56 PM
I am totally new to all this and I am trying to learn as much of this as possible before I spent $$ on trial and error.

I have read irrigationtutorials.com over and over and picked up a book on sprinkler systems.

I have completed dimensions and approximation of where I want to water and after checking with local code, my next step is to select a backflow preventor. I have noticed most installs on this forum uses a vacuum breaker (PVB), but since my highest sprinkler head sits in a retaining wall (sits pretty high off the ground), I have chosen to use either a Reduced Pressure Backflow Preventer or a double check backflow preventor since elevation of the BP would not be an issue.

Now which would be preferred and cost-effective (R.P. unit -or- Double check)? My county requires that it be ASSI code 1013 or 1020.
I have researched these brands: Febco 860/860U and Wilkins 975XL
Does anyone have any other suggestions? Brands/model
I was also wondering why Febco is cheaper to Wilkins by over $60

Does anyone suggestion going with a Double-Check Backflow preventer, if so why?

Dirty Water
10-25-2006, 03:06 PM
Doublechecks can be installed in a valvebox below grade. They don't have relief valves to stick open and are cheaper.

If your county allows them, go for it.

Kuma
10-25-2006, 03:15 PM
The Double Check backflow preventer is not rated for irrigation applications according to the USC Cross-Connection Manual. A Reduced Pressure Zone backflow preventer or Pressure Vacuum Breaker are rated for irrigation applications.

Dirty Water
10-25-2006, 03:16 PM
The Double Check backflow preventer is not rated for irrigation applications according to the USC Cross-Connection Manual. A Reduced Pressure Zone backflow preventer or Pressure Vacuum Breaker are rated for irrigation applications.

Not every county goes by the USC manual, my area for example, requires doublechecks and will fail you if you install a PVB.

As far as safety goes, A doublecheck should be inspected yearly for proper function, but I don't think a RPZ's toxic backflow rating is really needed in lawn sprinkler applications. Morgues, carwashes and factories yes, but lawn sprinklers? I'd fathom even a simple dual check would be fine.

silvercvic
10-25-2006, 03:17 PM
Doublechecks can be installed in a valvebox below grade. They don't have relief valves to stick open and are cheaper.

Do you recommend any brands/model? I would love to see an installed unit (valve box) if someone got one.

Also, the local plumbing store around me only carries a WATTS 009ms, anyone recommend this unit?

Dirty Water
10-25-2006, 03:20 PM
We exclusively install Febco 850's. I've found that the handles test to rust off on the Watts.

silvercvic
10-25-2006, 03:43 PM
We exclusively install Febco 850's. I've found that the handles test to rust off on the Watts.

Excuse my inexperience, but what do the 4 nozzles on top of the 850s do?

Wet_Boots
10-25-2006, 04:09 PM
Virginia is probably working to standards used by the BOCA codes, and cannot use double checks. {which would explain the OP not mentioning ASSE standard 1015} Best would be a PVB (pressure vacuum breaker) if you can install it at the needed height, otherwise the RPZ would be used. Eliminate the Febco 850 from your shopping.

jerryrwm
10-25-2006, 05:51 PM
Not every county goes by the USC manual, my area for example, requires doublechecks and will fail you if you install a PVB.

As far as safety goes, A doublecheck should be inspected yearly for proper function, but I don't think a RPZ's toxic backflow rating is really needed in lawn sprinkler applications. Morgues, carwashes and factories yes, but lawn sprinklers? I'd fathom even a simple dual check would be fine.

Jon, The reason they classify lawn irrigation systems as toxic is because of the chemicals that we put on the lawns, along with pet deposits, etc. It is pretty nasty stuff and it getting back in the potable supply is not something I want to deal with. The chances of this happening are pretty slim at best, but it only takes one time with some of those highly toxic chemicals and 'poof' someone dies or gets sick.

Double checks are only as good as their last test. They can fail and not be evident until the next time. A little thing like a piece of string can foul both checks. nd since they are many times buried in the valve box, there is a potential for cross connection if the box is flooded. In fact some areas have gone so far as to require a fitting/nipple/cap on each of the testcocks. And this nipple has to be above grade. These municipalities have the codes so that the valve box is not flush with the grade but at least 2" above grade so they can't be submerged. Real pain in the arse if there isn't a landscape bed to hide the box in.

And a dual check has no socially redeeming value other than being installed on a domestic supply line to the house. It might help keep the crap from the house from getting sucked into the city main.

RPZs and PVBs are still the only mechanical types of backflow prevention rated for toxic use.

Wet_Boots
10-25-2006, 08:06 PM
AVBs also carry a rating for toxic use, but they are not so widespread in usage. Their history of misuse, as taking the place of a PVB, has given them a poor reputation.

Since the regional plumbing codes I read are all requiring toxic-rated devices, there would be a point in looking to use them, where possible. DCVA users will no doubt be kicking and screaming if and when the rules change in their territory.

silvercvic
10-25-2006, 11:21 PM
Great info, all. I have decided on going with a RPZ, now some afterthought on my install since my plumber will be coming in a couple of days and I need to direct him on where to install the unit; either inside or outside the house. Since the utility room drain is across the room, I opted to place the unit outside 'above ground'.

Now my concern from this point is this, from another thread:

Let's suppose you install an RP device here. How are you going to winterize it? Aside from removing the RP entirely during the winter, there isn't a good way to winterize that system. You can winterize from the RP forward. But what about the pipe that's sticking up from the mainline to the beginning of the RP. You can't install a drain valve before the RP because that is a cross-connection and you can't have a cross connection before a backflow device. So you end up being stuck with a great backflow preventer, but one that breaks in the winter because of freeze damage.

Should I take this advice with a grain of salt? I looked on Febco's website and they indicate that a drain valve could be installed before RP unit as well as properly winterized as indicated here:

http://www.febcoonline.com/pdf/fp850-860.pdf

What exactly is a cross connection?

jerryrwm
10-26-2006, 12:32 AM
Great info, all. I have decided on going with a RPZ, now some afterthought on my install since my plumber will be coming in a couple of days and I need to direct him on where to install the unit; either inside or outside the house. Since the utility room drain is across the room, I opted to place the unit outside 'above ground'.

Now my concern from this point is this, from another thread:



Should I take this advice with a grain of salt? I looked on Febco's website and they indicate that a drain valve could be installed before RP unit as well as properly winterized as indicated here:

http://www.febcoonline.com/pdf/fp850-860.pdf

What exactly is a cross connection?


Technically it is any connection or fitting or apparatus on a potable water line that is, or potentially can, come in contact with non-potable/contaminated water. A hose in a deep sink is a cross-connection. Hooking a potable water supply from a utility purveyor to a private water well supply is a form of cross connection.

Wet_Boots
10-26-2006, 12:43 AM
The point of contention here would be a hose bib as a drain. Lots of old systems have them, for convenience of hooking up air for winterizing, and for leaving open all winter as a place for leaking water to escape. Some codes are written with the assumption that some idiot will connect a hose to something that could contaminate the water. Idiots, being what they are, could do just that. I'd still use a hose bib as a drain point, but be prepared to have a hose-thread vacuum breaker threaded onto it, for the sake of codes. One that can be removed, of course. This line of thinking can be amped up, and any drain with a threaded outlet could be frowned upon, by assuming the Idiots will have a threaded adapter to fit into the valve and connect a hose to. A plug threaded into the drain valve is supposed to eliminate the worries.

PurpHaze
10-26-2006, 08:19 AM
Great info, all.

For even more info go to this EPA web site:

http://www.epa.gov/safewater/crossconnection.html

You can view the EPA Cross Connection Control Manual document in HTML or download it in PDF format. It has a wealth of info on cross connections, devices, testing, etc. and is actually written in "user friendly" language. It is a valuable resource for anyone interested in cross connection.

PurpHaze
10-26-2006, 08:24 AM
Not every county goes by the USC manual, my area for example, requires doublechecks and will fail you if you install a PVB.

Funny... Even the EPA refers to the USC program since it's the world leader as far as cross connection info, testing, etc. is concerned. Perhaps your county should look further into it. :)

As far as safety goes, A doublecheck should be inspected yearly for proper function, but I don't think a RPZ's toxic backflow rating is really needed in lawn sprinkler applications. Morgues, carwashes and factories yes, but lawn sprinklers? I'd fathom even a simple dual check would be fine.

There are real and perceived dangers associated with cross connection potential problems. RPs and PVBs can also be a great deterrent to potential lawsuits.

HooKooDooKu
10-26-2006, 04:09 PM
Let's suppose you install an RP device here. How are you going to winterize it? Aside from removing the RP entirely during the winter, there isn't a good way to winterize that system. You can winterize from the RP forward. But what about the pipe that's sticking up from the mainline to the beginning of the RP. You can't install a drain valve before the RP because that is a cross-connection and you can't have a cross connection before a backflow device. So you end up being stuck with a great backflow preventer, but one that breaks in the winter because of freeze damage.

My solution was to install a wye filter (per the instructions of the BF device) underground and upstream from the backflow device. When I clean out the filter, that becomes my drain for the pipe leading to the backflow.

MOlawnman
10-26-2006, 07:19 PM
We install Febco 850's exclusively as well. The only reason we install an RPZ is if the local code requires it. The State of Missouri does not allow PVB's anywhere on anything. The minimum requirement is a double check on irrigation.

As far as a double check being only as good as the last certification, that goes for ALL beckflow prevention devices. That is why there is a place for "time of test" on most certification forms. When you test and certify a device you are certifying it for that exact time and date. If it fails after you tested it, then you have no control. Here in Missouri, all Backflow devices must be tested and certified every year.

I will stick by my choice of using a dcva until the state tells me that I must install an RPZ on new installs. Old ones will be grandfathered in.

Wet_Boots
10-26-2006, 07:39 PM
Got any reference on the 'no PVB allowed' policy? As for grandfathering in old work, don't bet the house on it. That can change with the next piece of legislation. Always, (almost always - examples, anyone?) the change in policy is to bring in toxic-rated devices.

MOlawnman
10-26-2006, 07:57 PM
There are installs with PVB's but code says that once they fail certification or need repair then it must be replaced.

Missouri does say that "grandfather is dead" and that nothing is grandfathered in. So I guess I did err on that front.

We could be here arguing the DC vs. RPZ vs. PVB discussion until hell freezes over and never come to an agreement. I think that some degree of protection is better than none. I still find systems installed with no backflow device installed whatsoever. And I have homeowner's complaining that there is no need for a device. I explain to them the importance if the device but they still complain.

Wet_Boots
10-26-2006, 08:22 PM
I can see a code being written on the basis of not trusting anyone's judgement of elevations, which a PVB depends on, but I never knew an entire state had codified that line of thinking.

PurpHaze
10-26-2006, 10:22 PM
Well............ It is the "Show Me" state. :laugh:

silvercvic
10-26-2006, 11:28 PM
Well, I double-checked with my county inspector and they said anything that is ASSE 1013 or 1020 (1020 require that it be 12" over the highest sprinkler). In my area, it seems that WATTS is the main company sold. Also found out that Febco got bought out by Watts, but no Febco dealer around me. I've kind of decided on going with the WATTS 009ms 3/4"...gotta spend more money :(

Now what baffles me on what the inspector said: If I install a drain valve after the main shut off and before the BF, I need to have a lock valve on it. Although they never indicated where the lock valve needs to be. I was wondering (from the manufactuer's instructions) whether I should install the lock valve before or after the drain valve.
Also if I should install inside or outside, Febco gives instructions on winterizing, but Watts states that it shouldn't be outside if my area has freezing conditions
http://www.watts.com/pdf/1911300.pdf
December/Jan/Feb/Mar=Freezing in VA

Wet_Boots
10-27-2006, 12:33 AM
Just have a low-point FPT fitting and thread a 1/2" plug in it. Nothing on that link says you can't install the 009 RPZ outside.

DanaMac
10-27-2006, 08:48 AM
Some companies put a hose bibb as a drain either in the basement just after the on/off handle, or outside where the pipe would ell/tee up into the BFP. To make it meet codes they will use a saw and cut off the threads so that a hose can not be attached. Or a fitting (ell or straight coupler) with the little cap drain can be used.

I have 3 RPs to replace that I replaced in April. They are all getting unions to remove it and possible auto drains immediately before the RP. The funny thing is the easiest thing they could do is just open the testc0cks.

If you install the RP in the basement, our codes here require some sort of catch basin to catch the water and pipe running from it to a floor drain.

PurpHaze
10-27-2006, 09:30 PM
If you install the RP in the basement, our codes here require some sort of catch basin to catch the water and pipe running from it to a floor drain.

A CCPD with a CCPD.

Dirty Water
10-27-2006, 09:49 PM
Funny thing about codes. A plumber can install a regular boiler drain on a water heater, or even a plumbing drain in the crawlspace that is technically "on the same line" as the before the sprinkler backflow preventer, but if we plumb one in between a shutoff and the backflow, it breaks codes.

Stupid.

Wet_Boots
10-27-2006, 10:42 PM
I don't think an installer-provided boiler drain would break any codes, if it were inside, where a basement shutoff valve was located.

Dirty Water
10-27-2006, 10:44 PM
I don't think an installer-provided boiler drain would break any codes, if it were inside, where a basement shutoff valve was located.

The other backflow thread (the one with pictures) a poster showed a picture of that install stating it was convenient but not to code. Since 99% of my backflow installs are out in the dirt, its not my problem :D

silvercvic
10-28-2006, 01:35 AM
Has anyone seen or installed a 'lock valve' before the BFD? I looked at every plumbing store in my area and no one has heard of a residental one, only big commerical ones with a key and no valve

Wet_Boots
10-28-2006, 03:14 AM
That's why the advice for a 1/2" FPT drain, with a sch 40 plug in it. Easy enough to remove with pliers for winterizing. There is a group of hose bibs known as 'lockshield' or 'loose key' where there is a high collar around the (short) valve stem, so it can't be operated by the Idiots who might connect a hose to something nasty.

PurpHaze
10-28-2006, 10:55 AM
That's why the advice for a 1/2" FPT drain, with a sch 40 plug in it. Easy enough to remove with pliers for winterizing. There is a group of hose bibs known as 'lockshield' or 'loose key' where there is a high collar around the (short) valve stem, so it can't be operated by the Idiots who might connect a hose to something nasty.

Nothing is perfect. Our plumbers use nothing but "loose key" hose bibbs but like anything else, they keep the honest people honest. The tubular guard can be easily removed and then pliers used to spall the valve stem.

We don't install hose bibbs at all when there is something that needs "hose water" from an irrigation system like pressure washers. We install QCVs for access with a QC key and hose swivel.

Wet_Boots
10-28-2006, 11:22 AM
My loose key hose bibs have the collar and bonnet as a single piece. But the stem has a slot across the end, so if the Idiot has a screwdriver, he can open the hose bib. I'm still leaning towards the idea of a removable vacuum breaker on a regular hose bib. It would be cool if one existed where the threading on of a (very?) special adapter would allow air to be blown into it.

Critical Care
10-28-2006, 11:32 AM
Not to stray too far off of the subject, but this is something that was in the news just a few days ago.

Some people in a small town just south of here got sick from e. coli, which they traced to the municipal water system. Out of about 140 or 150 people only several had backflow devices installed, and the authorities were a bit up in arms saying how difficult it was going to be to track down the source of contamination. But lo behold what was finally discovered was a rats nest in the town’s water system.

Dirty Water
10-28-2006, 12:16 PM
Not to stray too far off of the subject, but this is something that was in the news just a few days ago.

Some people in a small town just south of here got sick from e. coli, which they traced to the municipal water system. Out of about 140 or 150 people only several had backflow devices installed, and the authorities were a bit up in arms saying how difficult it was going to be to track down the source of contamination. But lo behold what was finally discovered was a rats nest in the town’s water system.


I think that a residential house is an easy scape goat for situations like this. If I had actually heard one first hand out account of a residential house causing some sort of trouble due to faulty backflow protection I'd be more apt to switch to RP's.

However, as long as my county lets me, I'm going to install doublechecks.

Wet_Boots
10-28-2006, 01:01 PM
It's hard to deny oneself the convenience of buried DCVAs - I used to love the extra time one had to winterize systems that were all below grade. Now that I've seen first-hand both failed DCVAs and line breaks caused by probes injecting toxins (termite killer), I don't mind the change.

I would still advocate using PVBs (except in Missouri, where they don't trust the inspectors to know which way is up :p) where possible, to get toxic protection at an economic cost. I can envision widespread unhappiness with a customer base that learns they have to have a BP replaced, if code changes require it.

Grassmechanic
10-29-2006, 12:11 PM
I'm still leaning towards the idea of a removable vacuum breaker on a regular hose bib. It would be cool if one existed where the threading on of a (very?) special adapter would allow air to be blown into it.
A couple of communities in this area require those style of breakers on hose bibs (yes, they have inspectors specifically for this and they do write tickets). What I had to do was unthread the breaker from it's permanently installed base, remove the diaphragm, and install a thick rubber o-ring in it's placeto keep the air from leaking. Then I rethreaded the breaker and blew it out with a simple hose adapter. When the winterization was finished, I merely removed my temporary o-ring and replaced the diaphragm.

Wet_Boots
10-29-2006, 12:32 PM
Since some hose-bib VBs are removable by loosening a locking hex screw, those aren't too much of a burden, if you have to have them.

Grassmechanic
10-29-2006, 12:51 PM
The ones they require aren't removable. Once they are threaded on, there are two or three "nails" that are driven into the hose bibb body. There ain't no unthreading those off, lol.

Wet_Boots
10-29-2006, 02:34 PM
Is there a separate ASSE number for the unremovable ones? All I can find for any version of the hose bib VBs is ASSE 1011, and usually those numbers are what codes will refer to.

Obviously, there is no easy answer to "Because I said so." in any encounter with local officials, but if one can find one of the ones that had a standard recessed-hex-head set screw, instead of the breakaway ones, (if they still exist) that might do. At least they won't unscrew, if checked for that.

MOlawnman
10-29-2006, 11:16 PM
Just another note on this thread. It wasn't until 2000 that my water purveyor started requiring annual tests and certifications on bfp devices. Yeah, we're kinda slow here. :confused: