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mxyplx

Severe Continuous Pipe Vibration When Valve(s) Open

mxyplx
11 years ago

I've wrote this up several times and tried to be brief and concise but it seems to get longer and longer because there are so many ifs. I hope this boiled down version paints the picture. I have studied this intensely on the internet, tried lots of combinations of things, spent many hours messing with it. Any and all ideas welcome. :-)

Copper pipe under house vibrated SEVERLY. Shook the house, rattled the dishes in the cupboards. This was not a couple bangs like water hammer it is continuous like a jack hammer. It does not stop until I flush a toilet or sometimes open a hose bib for a minute or less.

It only happens when valve(s) open.

Only with opening of these valves; sprinkler mostly, toilet & washing machine rarely. Inside faucets do not initiate vibration.

After reducing pressure from about 120 psi to about 50 psi (installed a PRV) the problem is reduced to this: Intensity of vibration vastly reduced.

There are 17 sprinkler valves. Any one may or may not trigger the vibration. The house was built in 1981 and the sprinkler systems installed mostly in 1982. Some valves have never been replaced. There wasn't a peep from the pipes till this summer.

The sprinkler circuits T off the main line upstream from the main house. The vibrating pipe doesn't even have water flowing thru it. The pipe is all PVC up to the house where it transits to 3/4 copper.

My conclusions are:

1. High pressure by itself is not the problem.

2. Loose pipes are not the problem.

3. Something obviously changed but what I cannot imagine.

4. Air in the pipes must be the prime problem.

Comments (9)

  • bus_driver
    11 years ago

    Are you sure that an older pressure regulator is not in the supply line somewhere and the new pressure regulator is an addition, not a replacement?
    If not, then you are saying that your system operated fine for years at 120 PSI without a pressure regulator. If so, that is simply amazing!

  • brickeyee
    11 years ago

    Doe the noise change as the valve opened further (or closed)?

    It could be as simple as a loose valve stem.

  • mxyplx
    Original Author
    11 years ago

    Hi- I wish. There are multiple valves. Mostly it's the sprinkler valves which are electrically driven basically open or shut with no stem. Perhaps one could flutter but why now after all these years? And they can't all flutter.

    The vibration may be stronger one time or another resulting in a noise change. Tomorrow I will crawl under and stuff old shoes and tires or what ever I can find here and there see if I can at least decrease noise if not the vibration.

    Hope I don't sound argumentative here. I've spent countless hours and walked a lot of miles just around the house checking/trying this and that. I cannot stop the vibration by pulling on the pipe. That will keep it from hitting a cross pipe but you can feel the vibration within the pipe and it is strong.

    Something is driving it. Driving me batty for sure.

  • brickeyee
    11 years ago

    PRV or back flow preventer are other candidates.

  • mxyplx
    Original Author
    11 years ago

    New meter. Same vibration. Nothing left to do but stand in the kitchen and eat everything in sight.

  • brickeyee
    11 years ago

    Disconnect the sprinkler system and see if it continues.

    Start eliminating things from the system one by one till you find the culprit.

    Some sprinkler valves are 'piloted' to reduce the force needed to operate them.

    They can cause all sorts of flutter issues under just the wrong conditions.

  • mxyplx
    Original Author
    11 years ago

    1. I disconnected the sprinkler lines front, garden and back completely from the house, physically and hydraulically, the pipes didn't even touch. Turned on each of the 3 hose bibs separately and the system vibrated. So!!!!!

    2. I disconnected the sooply line just downstream of the PRV (between the house and the PRV) and hooked up a simulated household pipe system (SHPS)*. It was about 23-4 feet of 3/4 PVC pipe with a PVC gate type valve glued on the end. It did not even touch the house pipes. No physical or hydraulic connection. Turned on the water, opened the valve and it uh - well it uh - well I'll be damned, the darn thing vibrated.

    I decided to use a long pipe section so that any vibrations would create a fairly large amplitude and be easier to detect. They could be felt as well as heard. Thus making it easier to prove to the city.

    Therefore the problem is NOT in the house or any of its components - it is in the supply to the house. Now it may be in the line between the street and the house which is my responsibility, not the city's, but it may be in the line upstream of the meter which is the city's problem. The meter man is scheduled to phone me Monday morning.

    I'm just happier than a pig in sh*t because my analysis was vindicated. :-)

    Just for completeness I did redo the experiment w/o the new PRV (tapped in just upstream of the PRV - between the PRV and the street) and got the same result at full city pressure proving that my new PRV was good and the vibration is independent of the PRV. It is a Wilkins which I gather is a good brand even if I did buy it at Lowes.

    *Simulate Household Investigative Tool (SH*T)

  • mxyplx
    Original Author
    11 years ago

    Followup:

    Skipping all the bloody details we found a PRV in the main supply line that has been buried for 31 years. Under some Saw Grass. One of its pipe fittings developed a split, I believe from the vibration, and leak which is how we discovered the valve. So there was an unknown and most likely unneeded 2nd PRV. It was easier to replace then eliminate. The vibration is gone - for now. This was a nightmare for several months.