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Water hammer and Backflow Preventer?

We recently purchased a home that has an irrigation/sprinkler system in place. With that system, we have a backflow preventer, as most cities require. One day after we had the system "turned on," the pipe leading to the irrigation system was shaking bad and I went out to the backflow preventer and it was releasing water from the bottom at the same cadence as the shaking of the pipe. After testing out scenarios, the shaking of the pipes (like a water hammer) and water coming out of the preventer is caused by shutting off the water too quickly in the showers upstairs or one of the toilets shutting off. Would this be a water hammer scenario, and if so, would applying a water hammer arrestor somewhere in the system work to avoid this issue? Thank you!!

Re: Water hammer and Backflow Preventer?

Yes i would think so. I would install several water hammer arrestors. You are supposed to have a least one on every hot and cold pipe for every branch.
What that means is two for the kitchen, two for the laundry room, two for every bathroom or powder room. on my jobs i install one for every fixture.
Water hammer can hammer pipe and fitting apart.

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