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Starting Member


Thursday, May 11th 2017, 12:08am

Backflow preventer

Hello All,
Bought a new house with a dirt yard and want to install a irrigation system before we have our yard sodded. I could not find my specific question/situation answered so I am posting a new topic. We have bi-level home on a lot with a very high slope in the back yard. We are in Wyoming, Michigan. The highest point of the slope is about 15 Feet above the basement level where I desire to install a proper back flow preventer. Installing in the basement right above the sump crock will give me a place to both drain the system and avoid freeze issues during the winter. Through my initial reading I am lead to believe an RPV would be a good choice. However, other comments imply a double check is the better and only choice. A little clarification would be appreciated as there is no possible way to install one "above the highest point" in my yard. Any other advice on system design and links would also be appreciated. Thanks in advance! Paul


Supreme Member

Posts: 482

Location: Houston, Texas


Thursday, May 11th 2017, 3:56pm

The main difference is that the Double Check Valve Assembly is a low hazard assembly. It protects against backpressure and Backsiphonage so elvation is not an issue. It does not have a vent or discharge capability. It is basically two check valves that need to hold tight at above 1 lbs pressure for check 1 and check 2.

The RP is a high hazard backflow preventer that is the best protection you can get. It is also a backpressure and backsiphonage protection. It does have a vent, that can discharge water. These are not supposed to be installed below grade. These consist of a first check must hold over 5 lbs pressure, relief valve open up at above 2 PSI, and the second check must hold tight at a value higher than the relief valve opening point.

Check with your local codes, in my opinion irrigation is a high hazard. But each community treats it differently.
I hope this clears it up a little bit.
:thumbup: :thumbsup:
LI0006121, BPAT0011021, CI0009500

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