SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

New York is somewhat complicated. There are some overlapping interests. Building codes, which are complicated by the existence of New York City, and there's the state Board of Health. If your DCVA did get declared unfit sometime in the future, don't complain. A DCVA is not inherently trustworthy over time, because internal parts can jam, and the device contains no air/water opening to help point out device failure. If the device is inspected on a yearly basis, by someone you have to pay on a yearly basis, then you are as good as the last inspection.

Quoted from "Wet_Boots"

PVBs are rated to protect against toxic backflow. This is fact in every location on our planet. RPZ devices are also rated to protect against toxic backflow. At present, most regional code authorities don't define a higher level of risk than "toxic backflow" ~ I do know that some state codes could have employed a classification of "lethal and/or sewage" and that there was no device whatsoever that was allowed in those instances (an "air break" could be used, but that was not an actual plumbing connection)

What I was getting at was the fact that PVB's are not rated for back pressure, only back-siphonage. RPZ's and DCVA's are rated for pack pressure as well as back-siphonage. RPZ's are the highest form of protection, with the exception (as you noted) of an air gap.



This thread points out the difficulties that arise when the original poster does not supply their location.

Agreed, but that doesn't mean that you should be useing the plumbing code that is enforced in your area to cover the OP's unknown code/area or enforcement policies.

I would always point towards the choice of toxic-rated backflow protection, because changes in codes almost always lead towards stricter standards. If there are localities with ordinances that require a DCVA, that would certainly be understandable, and those ordinances are no commentary on the fitness of a PVB .

With the exception of back-pressure

In New Jersey, there were numerous communities with DCVA-requiring ordinances, and those ordinances became null and void the moment the state adopted the National Standard Plumbing Code, with its mandating of toxic-rated backflow protection, without any grandfathering of older plumbing. (Of course the fun part was when numerous local plumbing inspectors did not act like they got the memo on the new state code, and continued to try to enforce the obsolete ordinances.)

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The important thing here, is that a properly located PVB provides its protection on the basis of gravity. Water would have to climb uphill in an open pipe in order to contaminate. Gravity is more trustworthy than all the lawyers and inspectors and legislators and insurance companies combined.

Gravity might be trustworthy, but put one under trained person 'that isn't quite sure about what's going on...' at the helm, and pressure (with your toxic waste) in the system will blow right past your infallible PVB's

If you can find an actual legal prohibition to the use of a PVB for toxic backflow protection, feel free to post a link to the legislation. I would like to read it. I expect what there actually is, is a disinterest on the part of inspectors and/or the local/regional governing body to verify that a vacuum breaker is properly installed. Far easier for them to require a device that is indifferent to elevation, even if it is less trustworthy over time than the PVB.

Code only regulates what is required or legal, rarely going into the ilegalaties. Yeah, I can see government all over the planet running to make laws that take PVB's out of use just because they want to have devices installed that are "indifferent to elevation". Why would anyone care about backpressure on a water system?

You missed the point boots,

I just said your statement that the "PVB would provide the highest level of protection" is incorrect. That belongs to the air gap, and the RPZ, regardeless of a PVB having the rateing to protect against toxic backflow. They lose the highest level ranking simply because of their design and function. They are not designed or required to protect against back pressure.

Mick

Quoted from "Wet_Boots"

New York is somewhat complicated. There are some overlapping interests. Building codes, which are complicated by the existence of New York City, and there's the state Board of Health. If your DCVA did get declared unfit sometime in the future, don't complain. A DCVA is not inherently trustworthy over time, because internal parts can jam, and the device contains no air/water opening to help point out device failure. If the device is inspected on a yearly basis, by someone you have to pay on a yearly basis, then you are as good as the last inspection.

A DCVA is legal and required in the OP's district.

Any testable backflow device is a mechanical device and by nature and defination will fail over time. Every device is only as good as it's last test with out the visual indicators.

Yes, I would like to have a visual indicator that any device has failed, before finding out during a test, but in Albany, NY, and Stony Point, this is what the requirements are. Live with it boots.


Mick

Quoted from "secutanudu"

I am concerned more about safety than meeting code requirements (usually they are one and the same). My town requires DCVA - and I would use something else (RPZ, PRV, whatever) if it means more safety, even if it is "against" code (despite being above and beyond code in reality).

My parents' town has no specific code requirement on type of backflow preventer. I installed a DCVA because I thought it was the most effective. Since their house is on a hill (the back is uphill from the house, the front is downhill), a PRV isn't feasible. Would simply replacing the DCVA with an RPZ offer the best long-term trouble-free protection?

Who would I call to do a test on the DCVA (yearly, I guess) if we decide to stick with it? Maybe the guy who blows out the system each fall can do it?

Thanks.

If you are more concerned about safety, go with a RPZ. A RPZ is an upgrade to a DCVA and shouldn't be a problem at all to the municipality. Verify with your municipality first.

Before you go with a RPZ, you will have to place it in an area that has a drain area for the possible venting, or have piping from the RPZ vent to a drain area.

The city should also have the names of certified backflow assembly testers to test your DCVA or RPZ. The system should actually be tested in the spring at start up, and only by someone that is certified.

Mick

If I were building a website like this, no one could post unless they supplied a location. Then we would not be playing guessing games about codes. By all rights, there should be no responses in a backflow thread where the OP doesn't first supply his location.

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Don't make book on your assumptions about backflow protection in New York State - it is very much a moving target. The Board of Health standards have been around for decades. Building codes are another matter. Water purveyors can step up and make their own demands. They can also turn on a dime and rescind their own rules. A number of Long Island communities were having installers use Dual Check Valves in their installs, (the small devices with no testcocks) and later changed their mind and had all the dual check valves pulled out. Installers were overjoyed. Some purveyors are even deciding it isn't their job to enforce Board of Health rules, so they tell installers to stop bothering them.

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I would always want to read the actual ordinance that requires lawn sprinkler plumbing to be a certain way. In many instances there are no ordinances that back up what someone tells you "is required" ~ don't take anyone's word on it. Read the written rules, and know.

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Because of it's spring-loaded air opening and gravity design, I believe nothing will ever be a better device than a PVB, so long as the elevation requirement is met. Gravity works, today and tomorrow and three years from now, when you happen to forget to have a DCVA inspected and repaired.

Quoted from "secutanudu"

Their DCVA is actually located outside, which annoyed me at the time of installation by the plumber (I did all the work downstream of the DCVA). I knew it could be installed inside, i think the plumber may have thought it was an RPZ so he put it outside for drainage. Maybe it's just as well, if we switch to an RPZ and water drains out of it, no problem.

How does an RPZ work? Do they leak water when backflow happens? Any reason not to leave the DCVA in also (along with an RPZ), since we already have it?

I just called the my parents' town, and the guy in the building dept. had no idea what i was talking about when I asked about backflow preventers for a sprinkler system...I probably got the wrong guy.

The DCVA is installed outside sometime for ease of testing. You or your parents don't have to be home to let the tester do his thing.

During a backflow event (if there is a malfunction) the RPZ will vent water to eliminate the possiblitiy of contaminating the potable water supply.

If a DCVA is currently allowed there is no reason that you can not use it.

Mick

Quoted from "Wet_Boots"

If I were building a website like this, no one could post unless they supplied a location. Then we would not be playing guessing games about codes. By all rights, there should be no responses in a backflow thread where the OP doesn't first supply his location.

Don't make book on your assumptions about backflow protection in New York State - it is very much a moving target. The Board of Health standards have been around for decades. Building codes are another matter. Water purveyors can step up and make their own demands. They can also turn on a dime and rescind their own rules. A number of Long Island communities were having installers use Dual Check Valves in their installs, (the small devices with no testcocks) and later changed their mind and had all the dual check valves pulled out. Installers were overjoyed. Some purveyors are even deciding it isn't their job to enforce Board of Health rules, so they tell installers to stop bothering them.

So what you are saying is that you should always have your location included so that we would not be playing guessing games about codes, except if you are living in New York. In that case you will always be playing guessing games about codes.

Mick

Quoted from "Wet_Boots"

I would always want to read the actual ordinance that requires lawn sprinkler plumbing to be a certain way. In many instances there are no ordinances that back up what someone tells you "is required" ~ don't take anyone's word on it. Read the written rules, and know.

You should be reading the written rules for any code, lawn sprinkling or otherwise.

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Because of it's spring-loaded air opening and gravity design, I believe nothing will ever be a better device than a PVB, so long as the elevation requirement is met. Gravity works, today and tomorrow and three years from now, when you happen to forget to have a DCVA inspected and repaired.

Good for you boots. You have the right to believe that. Yes gravity will work the same for the foreseeable future, but so will pressure, cross connection possibilities/probabilities, and humans not thinking.

Are PVB's immune from testing? Don't think so. Last I looked, they still have to be tested the same as DCVA's, and RPZ's. PVB's will have the same problem's as others if they fail, stick, or have critters crawl inside and nest in them during the off-season. Being that they also have vented openings, they are subject to things getting inside of them. They all should be tested at least annually by a certified backflow assembly tester.

Mick