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Help with loud plumbing

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Aug 29, 2013, 09:32 AM
Help with loud plumbing
This morning at 4:00am we awoke to what sounded like a helicopter. We tracked it down to the plumbing. Our pipes out front are exposed and we have an irrigation system that was running at the time. We shut off the irrigation and it stopped. Noise does not occur when flushing or running a faucet. When the noise was occurring there was a lot of vibration in the pipes out front. There is a backflow preventer (same as anti-siphon?) on the system. Is this a issue with the backflow, or the meter or the sprinkler control? Just not sure who to call or what to tear apart myself. Thanks much!
Aug 29, 2013, 01:24 PM
the backflow preventers we have don't add any noise on a full water flow. but operate any other water user, even the icemaker, with the faucet on and the water stopped outside, and they whine like a bassoon tuning up. it's the nature of the beast, they are responding to an effective backpressure.

our lines are strapped down well, so that isn't the issue.

(looking around for inspectors.....)

if you have an above-ground sprinkler going that is not going to have a chance to introduce any "outside" water under any circumstances, you can take off the backflow preventer "for a functional test." but it has to go back on for any possible connection of a water reserve, such as using a bottle sprayer. absolutely.

sig: if this is a new economy, how come they still want my old-fashioned money?
Aug 29, 2013, 03:59 PM
This was a "suddenly there" noise that has not been present before. It was a constant sound like the sound helicopter blades make. The exterior and interior exposed pipes were vibrating with the same pulse. This is not the one time bang you sometimes hear in pipes, but a continuous thump thump thump.

I saw instance on the internet that the backflow preventer or the meter could be the issue. I guess my questions are based on the symptoms, which is it?
Aug 29, 2013, 04:00 PM
Maybe I'm using the wrong word. Maybe anti-siphon device? Is that the same as backflow? It is outside installed on the main lines of water.
Aug 29, 2013, 06:06 PM
I have a pressure reducing valve out there too. Hmmmmm!