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

Backflow testing is strictly for pros - not because no one else could do it, but because it's an "official" activity, done by people that possess certifications and licenses to do the work, and performed with equipment "officially" calibrated by test labs. No homeowner would ever be able to generate the necessary paper trail involved.

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The Watts 909 series of RPZs is an old product line, and an expensive one at that. You can google a better price than $578, though. I would want to read the published code that requires you to use a particular make and model of backflow preventer. It may not exist, and all you hear when you ask someone at town hall, may be someone's personal preference. There are specific standards met by backflow preventers, and it is those standards that written codes should be referring to, such as ASSE 1013 for an RPZ assembly. If they would allow you to use the more modern Watts 009 RPZ, you could find one for around $200

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By the way, the use of a Watts 288 as a whole system protector is entirely bogus. it never ever met any code requirement in that application (it's an atmospheric vacuum breaker) ~ As for basement installation of an RPZ, it would only be workable in an industrial environment, in a room with a high-capacity floor drain that can handle the entire incoming flow of your home's water supply (in the event of an internal fault in the RPZ)

Quoted from "Wet_Boots"

...As for basement installation of an RPZ, it would only be workable in an industrial environment, in a room with a high-capacity floor drain that can handle the entire incoming flow of your home's water supply (in the event of an internal fault in the RPZ)

In-part, the way an RPZ works is that if backflow attempts to occur, or if the device has a critical failure, it will discharge water out of a discharge port rather than allow the water source to become contaminated. And even under normal operations, it's possible for the RPZ to spit a little water when irrigation valves open/close just because of the changing pressure dynamics of the system. The device's weakness is that it can fail if it becomes submerged. So these two things taken together generally means an RPZ must be installed in an above ground "out doors" location. However, unlike a AVB or PVB, the elevation of the RPZ relative to the sprinkler heads does NOT mater.


As for the valves on each end of the device? That's so the certified technition can test the device in-place.

Tread carefully when you are getting information from town officials who may not like it when their word might be questioned. One independent source of information can be the local library, who should have a copy of town ordinances, possibly at the reference desk.

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By the way, you don't have to have a Y-strainer upstream of the RPZ when it's installed outdoors - not that the strainer is a bad thing, but it might make for a big savings if you get an RPZ without it. The $575 price for the 1-inch 909 might have been for the assembly that includes a strainer.

As a tester, I would like to say. If the RP is installed inside, it does need to be connected to a drain. It needs to have 12" of elevation from floor to device. The handles on the device need to be functional or positioned so they can be opened and closed. The Test Cocks need to have room or 6" or so of clearance to connect the pressure differential guages to.

Then is would be ready to be inspected. Paper work is the key as metioned in earlier posts!!

Not safe and not reasonable - installation must also take malfunctions into account, and they could have the relief valve wide open and continuously dumping all the inlet flow. There is a reason you have floor drains for indoor installs. Read the installation instructions.

Quoted from "dwinmac"

Quoted from "HooKooDooKu"

RPZ must be installed in an above ground "out doors" location. However, unlike a AVB or PVB, the elevation of the RPZ relative to the sprinkler heads does NOT mater.

As for the valves on each end of the device? That's so the certified technition can test the device in-place.

Can someone give me a backflow device type and associated manufacturers that would be safe to use in the basement. As I understand it there are 5 types:
1. Air-Gap
2. Atmospheric (non-pressure) Type Vacuum Breaker
3. Pressure Vacuum Breaker {PVB}
4. Double Check Valve Assembly {DC}
5. Reduced Pressure Principle Assembly {RP}

I will take this information back to the town to see what they have to say about it. I will ask them about written codes such as ASSE 1013.

Relative to testing, I definitely want to leave that up to the experts; but, I am wondering if the backflow device has to be installed in such a way to allow the expert to test it or are there test ports built in to all backflow devices.

The only device that can EASILY be installed in a basement is the DC. The only requirements for its instilation is that it be accessable for testing. However, the DC is on the lower end of the scale as far as protection is concerned (Air gap, PVB, and RPZ offer more protection) and therefore it is NOT appropriate for systems that inject anything into the water (as in including ferdigation with your install) and many municipalities may not allow it.

I think Wet Boots point was that it is odd that the city would specifically require Watts 909, but your local law very well might require an RPZ (and the inspector is perhaps most familier with the 909).