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

Seems to me you should look at what is causing the backflow device to dump, rather than just replace it with one that would not readily show a pressure loss problem in its operation. Even if you put the DCVA in, the problem is still there and will just show up elsewhere , maybe in a different fashion. Sufficient information on your set up has not been given to really diagnose this problem. Are you on a well or city water? Are you watering steep slopes ? There are lots of possibilities.
For every area that allows a DCVA in an irrigation system there is one that does not. You have to check with your local authorities. In my area it is a properly installed AVB, PVB, or an RP Assy. I believe the National Irrigation Association views irrigation systems as high hazard in their standards. I would agree with Todd that you are taking a step back in protection by installing a DCVA over a properly installed PVB.

Mitchgo thanks for the reinformation.

I did not realize you have read all of the regional health codes. I have not.

I think you are just wrong in your view!! How can you encourage somebody to go from a High hazard device to a Low hazard device with out first understanding why there was a High hazard device in the first place?

Well, I've been in this argument before.

I'm not encouraging someone to go from high to low. I never told the guy to get a double check, I actually said he pvb is working correctly and doing it's job. However when the potential of a problem from a irrigation system is low, I don't see a problem in saying it's okay to use a double check.

My main reason why I support double checks is because they are rated to go below ground.. Which in my opinion a green box in the ground looks sooo much better then a piece of copper pipe and brass assembly sticking above the ground somewhere around the yard/ house.. rp's can go underground too as long as they have proper drainage.. Which for a rp could be difficult

My second reason is because I personally feel double checks are completely fine for irrigation systems. I think All back flow devices should be tested Annually, or every 2 years to ensure they are properly working.

I was just in hawaii and saw Many many Rp's and PVB's next to street curbs and meters . horrible and ugly installs . Soo many potential hazards.. not to mention crack heads can easily steal them.

Quoted from "Mitchgo"

Well, I've been in this argument before.

I'm not encouraging someone to go from high to low. I never told the guy to get a double check, I actually said he pvb is working correctly and doing it's job. However when the potential of a problem from a irrigation system is low, I don't see a problem in saying it's okay to use a double check.

My main reason why I support double checks is because they are rated to go below ground.. Which in my opinion a green box in the ground looks sooo much better then a piece of copper pipe and brass assembly sticking above the ground somewhere around the yard/ house.. rp's can go underground too as long as they have proper drainage.. Which for a rp could be difficult

My second reason is because I personally feel double checks are completely fine for irrigation systems. I think All back flow devices should be tested Annually, or every 2 years to ensure they are properly working.

I was just in hawaii and saw Many many Rp's and PVB's next to street curbs and meters . horrible and ugly installs . Soo many potential hazards.. not to mention crack heads can easily steal them.

Below-grade mounting is absolutely, positively, no reason to downgrade system protection. In the giving of advice, location must be pinpointed. Then advice can follow. Conjecture and aesthetics need not apply to a question on backflow.

Quoted from "wsommariva"

Op here. Why am I wrong for getting a dcva? From what I've read, it works. My town seems to require "a" backflow preventer device. EDIT: my town allows anti siphon valves, double check valves, PBV and one other type that I can't remember. Secondly that PBV, from what I've read can open up and cause floods. Why take that chance?

Not that it matters now, but noone answered my comment about the auto drain plugs that I have installed and if that can cause a PBV to gush water.

BTW, my system works great.

I bought a Febco DCV

Anyone want a free slightly used Toro PBV?

You have received incorrect information from your town. The state of New Jersey requires toxic-rated backflow prevention for lawn sprinkler systems. This has been the law for over 20 years. That a municipal office hands out incorrect information is not all that unusual, especially if their learning comes from before 1990.

no Double Check Valve Assembly is fit for lawn sprinkler use in New Jersey. Even older systems with them became code violations when the law was changed. No grandfathering was a part of the law. If it happens that you can find a DCVA at a big-box store, understand that they are not founts of correct information.

If you still have doubts about this (I certainly don't, since I've done work in the area, and am obligated to know what's what) go to your library and read up on the codes. When New Jersey changed the rules, they took their new plumbing rules from the National Standard Plumbing Code and made it a part of the state's building codes. This is state-wide. The only discretion allowed to any municipality, is for them to make the rules even more stringent.

Keep the PVB. Lose the auto-drain valves. Later on, maybe take another look at the supply plumbing, because sometimes the chief cause of lowered pressure is pressure loss in the supply plumbing.

Again, forget the DCVA - they were all the rage in the 1980's - not any more, especially in any state that adopted a regional plumbing code like the NSPC. When the code changed, many sprinkler guys, including me, were angry, because we were thinking nothing could be more convenient than a basement installation of a DCVA. We could even have the supply plumbing exit the house below grade, and have protection from overnight freezing.

Turns out, though that it was a change for the good. We learned that the most popular model of DVCA turned out to have a problem with internal parts sticking. All those DCVA installs were trouble waiting to happen, especially since there was not any requirement for the devices to be inspected on a yearly basis. That a DCVA can fail with no indication of malfunction is why they are not rated to protect against toxic backfow.

Any properly installed vacuum breaker gives you protection based on gravity. As long as gravity is still around, water cannot flow uphill in an open pipe, and your (and your town's) drinking water is protected. Gravity beats check valves, hands down.

No way should a RPA assy be put in an irrigation box below grade. Besides the possibility of flooding the box and submerging the device,there certainly would be a difficulty in testing and making repairs. No one is going to set up some elaborate drainage system within a valve box to allow for its relief valve opening.
New Jersey has very specific regulations on the installation of sprinkler systems and I too am doubtful that your getting good info on what is an appropriate backflow device. High hazard devices are only appropriate. If your still questioning the recommendations of three on this board, contact the Irrigation Association of New Jersey and they will verify the requirements. Fix the pressure problem and stick with the PVB.