Basement Sewer pump vibration

Discussion in 'Plumbing Forum' started by Rten, Feb 12, 2010.

  1. Feb 12, 2010 #1

    Rten

    Rten

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    I have read several postings here on the subject and am seeking additional information. I too have a pretty severe vibration that lasts 15-20 seconds after the pumps shuts off. I suspect a leaking check valve. I have a brass housing check valve that is mounted horizonally about 10 feet above the pump discharge. The system made some noise but got much worse after I replaced the sewer pump with a new Hydromatic SP-40 that has a pressure diaphram type cut off switch (same type pump as old one). I read here that installing a radiator hose could help isolate the vibration. I plan on replacing the 2 in check vlave with a new "quite-type" rubber flapper check valve. I have the following questions.

    1. Should I mount the valve horizonally or in the vertical? (The pump manufacucture said mount it horizonally)

    2. Do I need to drill a small 1/8 " hole in the discharge line just above the pump in the sump to prevent air cavatation?

    3. Spring vs rubber flapper type valves? ( 1/2 psi required to open)

    4. What about magnetic valves? ( a greater 2 psi required to open)

    5. Best location for corregated radiator hose isolator?

    6. Will putting the pump on a rubber base or feet really help?

    7. How do I stop the vibration?

    Thanks a Million..........."A big vibration with every flush".....Help
     
  2. Feb 12, 2010 #2

    Redwood

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    I would install a new silent check on the vertical just above the pit with rubber couplings.

    Radiator hoses belong under the hood of your car.
     
  3. Feb 12, 2010 #3

    Rten

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    Thank you Redwood but are you also saying that I should not put a plumbing check valve under the hood of my car?............
     
  4. Feb 12, 2010 #4

    Redwood

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    Yea I guess so....
     
  5. Feb 12, 2010 #5

    Wuzzat?

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    What takes 15 to 20 seconds to wind down and
    has enough stored energy [with no pump to feed it]
    so as to cause a vibration [not just a noise]?

    Can you post a YouTube video of the noise?

    Is the vibration like the buzz of a fluorescent tube [120 Hz]?

    Is it like the 10 Hz vibration of an ABS coming on because of slippery pavement?

    Is the vibration of such an amplitude that you can see it?

    Does holding onto pipes damp out the vibration?

    A surgical rubber tube should do better in damping vibrations than a much-less-compliant radiator hose but I don't know if anyone makes a tube this large from surgical rubber.
    As a prototype damper you could cut the ends off several long balloons and put one inside the other to make a resilient and strong tube, and clamp them to the more rigid piping. One balloon can withstand about 1/2 PSI and a 6' high pipe needs about 3 PSI to pump water out of it.
     
    Last edited: Feb 12, 2010
  6. Feb 12, 2010 #6

    Rten

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    In my frenzy to find a solution to the vibration I would like to plead guilty to the charge of over estimating the length of the vibration. It is probably closer to 5-8 sec. The water in the pipe seems to be flowing backwards to the sewer pump as the pressure switch closes causing the low frequency vibration that agressively shakes the 2 inch pipe. Yes you can see and feel the pipe vibrate and hear it troughout the house. Another post suggested using a corragated radiator hose to isolate the vibration. I just got a Magic plastic spring loaded check valve that is advertised to reduce noise. Wish me luck.
     
  7. Feb 12, 2010 #7

    Wuzzat?

    Wuzzat?

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    It sounds like compliant pipe couplings cause the problem, but they may be there to solve other problems. Also, the pipe may just happen to be resonant at the vibration freq., so what starts out as a small amplitude shaking gets greatly magnified.

    Since you can reliably reproduce the fault, use clamps or your hands to mechanically couple the pipe to a rigid surfaces. This should damp it out.
    But watch out this doesn't overstress pipe joints, which would cause later failure due to fatigue.

    Another way would be to isolate a vibrating section of pipe from the rest of the house using your patent pending party balloon isolation device [PPPBID].
    You heard it here first!

    But it might sell better if it had a German-sounding name.
    This girl
    http://www.oddcast.com/demos/tts/tts_tran_example.php?clients
    tells me it translates to
    dieser Erfindung ist dumm
    :(
    but she has lied to me before.
     
    Last edited: Feb 12, 2010
  8. Feb 13, 2010 #8

    Redwood

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    One of these would be what you need to use...

    [​IMG]

    This is a plumbing fitting...
    Not a radiator hose...
    Not surgical tubing...
    A Plumbing Fitting...
     
  9. Feb 13, 2010 #9

    Wuzzat?

    Wuzzat?

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    Those Fernco couplers are pretty stiff.

    I had something in mind more like the coupler on page 14 of
    http://www.thevmcgroup.com/PDFs/vmcspec.pdf

    "Series "VMS" and "VMT"
    Quiet-Sphere Flexible Connectors
    Single-sphere (VMS) and twin-sphere (VMT) connectors are
    molded of neoprene and synthetic fiber and furnished with
    corrosion resistant floating steel flanges. Operating temper-
    ature to 240°F and operating pressure to 214 psi.
    Compensates for expansion, compression, transverse
    movement, and angular deflection. Reduces vibration and
    noise transmission. Size 1-1⁄4" to 20" I.D. "

    if somebody makes a residential version of this coupler.

    The graph on page 2 of the link shows the dependence on frequency.
     
    Last edited: Feb 13, 2010
  10. Feb 13, 2010 #10

    kok328

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    Install a rubber flapper check valve no more than 2ft. from the pump on a vertical portion of the discharge pipes. The rubber check valve is similar material as a Fernco coupler and will do just fine in reducing vibration. The reason for your vibration is related to the location of your existing check valve, the material construction of your existing check valve and the horizontal installation of your existing check valve.
     
  11. Feb 13, 2010 #11

    Wuzzat?

    Wuzzat?

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    Which leads to several quotes from the Web.

    From the sources below it seems like the OP has 'chatter'. The weight & speed of the falling water causes turbulence.

    Below, 'D' seems to refer to pipe diameter.

    All check valves should be installed at least ten pipe diameters away from upstream pumps, elbows, fittings or equipment.

    Many check valve manufacturers have in their literature a requirement for 5-6D between pump discharge and check valve. In fact Velan recommend 10D.
    The reason is that there can be turbulence from the pump that increases the wear of a check valve and lead to its failure.

    If there are any fittings, control valves, orifices, etc., close to the check valve they will cause turbulence. This may result in "chatter" and premature failure of the check valve. Our standards require straight runs of 5D upstream and 2D downstream of the check valve. Although you have not mentioned the type of check valve being used, 8D sounds very conservative. A 1D distance is too close for any type of check valve in continuous service.

    The preferred installation of a ball check is in the vertical position. This will insure that
    gravity will seat the ball properly each time. However, if the ball check valve is to be used in a
    horizontal installation, it is important that the static head is at least 20 feet of water (nine pounds per
    square inch). Recommended flow velocity range is 3-5 feet/second (if a higher flow velocity is
    required, please consult the factory). Ball check valves with a floating ball should be installed in a
    vertical orientation only and have a minimum of 10 feet of static head to seal correctly. Do NOT
    subject ball check valves to freezing conditions.
     
  12. Feb 13, 2010 #12

    Redwood

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    Okay what would I know...
    I'm just a plumber that has done more installations in the last 35 years than I could ever add up...:rolleyes:

    Use the Fernco put the "Silent" or, "Quiet" Check Valve vertical a short distance above the pit and put a valve above the check valve so it can be serviced easily at a later date. Support the pipes adequately above the pit and your installation will be quiet.

    It's just the way it is...
    The Fernco couplings provide the vibration isolating needed from the pump and the silent check valve and proper pipe supports will take care of the rest...

    We don't need to have a NASA consultation here...:cool:

    For the valve and check valve I usually install the A.Y.McDonald # 2066S 2

    [​IMG]

    http://aymcdonald.com/products_categories.cfm?prodline=Plumbing&groupID=73&catID=13

    With a Fernco below it for pump vibration isolation.
     
    Last edited: Feb 13, 2010
  13. Feb 13, 2010 #13

    Wuzzat?

    Wuzzat?

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    Bingo!
    I was at Goddard SFC from '74 to '81.
    Didn't do check valves, though. . .:(
    We did
    Sounding rocket - Wikipedia, the free encyclopedia

    BTW, based on the rules above I think my sump pump check valve which is still working is installed incorrectly.
     
    Last edited: Feb 13, 2010
  14. Feb 13, 2010 #14

    Redwood

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    LOL
    That must have been some neat stuff to work on...:clap:

    I imagine the vibrations and their resonant frequencies are a little more severe in that application along with their consequences.
     
  15. Feb 13, 2010 #15

    Wuzzat?

    Wuzzat?

    Wuzzat?

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    Well, we didn't blow up stuff like
    wikipedia.org/wiki/Vanguard_(rocket)

    We worked on telemetry, when we weren't fixing peoples' radios, depth finders, RC toys, etc.. We actually had a tube tester in the lab [our sounding rockets did not use vacuum tubes].

    One of our experiments flew on
    wikipedia.org/wiki/Getaway_Special

    Looking back, it was fun. It wasn't at the time.
    "I wish I didn't know now what I didn't know then"
     
    Last edited: Feb 13, 2010
  16. Feb 14, 2010 #16

    Rten

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    Thanks to all for the replys to my plumbing vibrations problem. I will use your advice and install the silent type rubber check valve in the vertical pipe just above the sump. Sounds like this should solve the problem.

    Cheers
    Rten
     
  17. Feb 16, 2010 #17

    Rten

    Rten

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    Well I finally installed a Magic plastic silent check valve in the vetical pipe just above the sewer sump. I also drilled a small 1/8 inch hole angled down in the discharge pipe approximately 2 inches above the top of the pump in the sump. (prevents possible cavatation). This installation reduced the vibration by 90 % or so which I can live with. I get a very slight vibration that lasts a second or so just as the pump shuts off. I suppose I could futher reduce the slight vibration by installing a rubber coupling between the pump and the check valve. Thanks again for the advice.

    Rten
     
  18. Feb 16, 2010 #18

    Redwood

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    That would complete the noise reduction job...:beer:
     

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