Vibration and knocking / shaking from submersible well pump system

Discussion in 'Pumps and Tanks Well Forum & Blog' started by cpowers, Aug 25, 2012.

  1. cpowers

    cpowers New Member

    Messages:
    8
    Location:
    indiana
    Ok, First time post. I have looked for answers elsewhere but i think my inexperience has hampered my finding any solutions. I have a 7-10 year old 240 ft deep well here in northern indiana. i have no water problems (other than calcium/iron) plenty of supply and good pressure. Alas, since i have lived here (5 years) when the well kicks on (appx 30psi) there is a noticble vibration in the supply line (pex?). This vibration transmitts from the joist to the dining room etc essentially making my whole floor a speaker. When the pump kicks off (appx 70psi) i get a slight knocking, this is because the pipe is actually shaking back and forth.

    Driving me crazy, if there is a reasonable repair i would be all about it. Since a picture is worth a thousand words i have linked to a short video. the sound is pretty muffled, but i think it will be able to pass more info on to you.



    http://youtu.be/5kzT2SNMErw



    Pressure tank is a welltrol
    switch is square d

    Thanks so much!
    Chris
  2. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    3,827
    Location:
    NW Ontario, Canada
    The problem you are having is water hammer most likely caused by a bad checkvalve in the pump. It would be good to know if there are more checkvalves in-line in the drop pipe or at the wellhead. When the one in the pump goes, the others quickly follow like dominoes. I didn't see one at the tank in the video. When the pressure switch kicks on, is there any delay before it flows?

    In my home I deliberately strapped my poly pipe to the underside of the floor joists so that I can hear when the water flows. My thoughts at the time was that if it was too loud, that I would replace the metal pipe strapping with rubber to isolate it but didn't find the noise to be too bad.
  3. cpowers

    cpowers New Member

    Messages:
    8
    Location:
    indiana
    Is there a way to remedy this without pulling the pump? I hate to cause more damage especially with my level of experience. also spending $500 or more would be less than optimal.

    Thanks!
    Chris
  4. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    3,827
    Location:
    NW Ontario, Canada
    If it is the checkvalve(s) as I suspect, pulling the pump is unavoidable. How deep is the pump hung and what is the static water level at? You did not answer my question about a delay.

    I cannot tell from the video how bad it really is so you might want to get a pro to look at it and give his/her assessment. The bouncing of the needle at shut-off supports my prognosis of water hammer. Problems of water hammer don't fix themselves and cause stress leading to more component failure. I cannot comment on the cost.

    Also, I cannot tell how well your bladder tank is performing WRT how much drawdown it has and if the precharge is optimal. Rather than use a tap upstairs to test, you should be drawing from the draincock at the tank. Measure how many gallons of drawdown there is and compare it to published tables for your size of tank. Then check the precharge and make sure both your air and water pressure gauges are calibrated.
  5. valveman

    valveman Moderator Staff Member

    Messages:
    4,370
    Location:
    Lubbock, Texas
    30 to 70 is a very wide bandwidth for the pressure switch. When I see this it tells me someone is trying to extend the run time and limit the pump cycling. The problem is you can only put in 28 PSI of air, so by the time you get to 70, there isn’t much cushion left in the tank.

    When the pump starts at 30, it is pumping very high volume, and you are probably hearing pipe rattling from high water velocity. When it gets to 70 and shuts off, the check valve slams and without enough cushion in the tank, the gauge bounces a few times, which means the pipe is expanding and contracting, bouncing off the floor joist.

    A Cycle Stop Valve would help by eliminating the water hammer on pump start and stop, as well as limiting the velocity when pumping. It would also eliminate the cycling and allow you to reset the pressure switch to a more normal 40/60, so you don’t over-stretch the bladder in the tank.

    If it still makes noise while pumping after adding a CSV, the only other thing I can think of would be the length of pipe down the well. Sometimes the length of pipe is accidentally the right length to match the wave length of the running frequency of the pump/motor. This causes a harmonic vibration that can only be solved by shortening or lengthening the drop pipe a foot or two.

    You also might try hanging the pipe underneath from rubber pipe hangers.
  6. craigpump

    craigpump Member

    Messages:
    850
    Location:
    ct
    You might also give some serious consideration to getting rid of that galvanized nipple under the pressure switch. I have seen extreme examples where those nipples plug, the pump doesn't shut off and the tank bursts.

    Not pretty
  7. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    3,827
    Location:
    NW Ontario, Canada
    I've reviewed the video again and concur with what valveman said, taking back my prognosis of a bad checkvalve. Hang the pipe using rubber strap and install a CSV. Also, as craigpump said, lose that galvanized nipple and install a PRV if you don't already have one somewhere in-line.
  8. cpowers

    cpowers New Member

    Messages:
    8
    Location:
    indiana
    Well, (cough cough), there you go. Ounce of prevention. I neglected to make any adjustments and now i have what i am sure is a holey bladder. My pump has been cycling very frequently in the last week, and when i went to listen to the tank etc the pump is able to 'fill' the tank from 30 to 70 psi within about 5 seconds. This is accompanied by a trickling water sound. A typical (low flow) toilet flush requires two cycle on's.

    I obviously need to replace the tank, but seeing as i have multiple concerns i am very near just buying the pside kick. Are there any other recommendations before i pull the trigger?

    Thanks
  9. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    3,827
    Location:
    NW Ontario, Canada
    You need to track down why you are hearing that as it is not likely related to the bad bladder but first off, get some air into that bladder as a stop-gap.
  10. cpowers

    cpowers New Member

    Messages:
    8
    Location:
    indiana
    water flowing sound is inside of bladder tank. tank is solid sounding water logged and schrader valves sprays water at me. i added several gallons of air to get by until i get parts.

    Chris
  11. Wet_Boots

    Wet_Boots Sprinkler Guy

    Messages:
    798
    Location:
    Metro NYC
    Is a 40 psi range even commonly achievable in a standard Square-D pressure switch? I never tried for it, as there was no point in having low supply pressure for my work.
  12. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    3,827
    Location:
    NW Ontario, Canada
    Tightening the smaller of the two springs increases the spread. The large spring moves both setpoints roughly in parallel.
  13. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    3,827
    Location:
    NW Ontario, Canada
    Increasing the spread will hasten the demise of the bladder as it stretches it beyond design limits.
  14. Wet_Boots

    Wet_Boots Sprinkler Guy

    Messages:
    798
    Location:
    Metro NYC
    I was thinking in terms of whether a 40 psi spread was beyond normal limits, which would make a rusted-up galvanized nipple to the switch a suspect. I've encountered those before, and they made for a shut-off pressure that was above what the switch was actually set for.
  15. valveman

    valveman Moderator Staff Member

    Messages:
    4,370
    Location:
    Lubbock, Texas
    A busted bladder in a tank can make all kinds of strange noises. Adding air usually doesn’t help as the bladder is broken and stuck against the inlet/exit hole.

    Even with the 4.5 gallon tank (1 gallon of water) in the Pside-Kick kit, the CSV will make the pump stay on until the toilet is full and then another 30 seconds to refill the pressure tank. You won’t know how bad cycling the pump was until you experience constant pressure with no cycling from a CSV.
  16. craigpump

    craigpump Member

    Messages:
    850
    Location:
    ct
    A lot of times adding air to a tank with a ruptured diaphram or bladder results in the system being loaded with all the sediment that has accumulated in the tank over the years.
  17. cpowers

    cpowers New Member

    Messages:
    8
    Location:
    indiana
    Sorry about the delay, i actually replaced everything on 11/2/13. I did not get the csv due to time constraints. i did upgrade to a 44 gallon tank. I was unable to reuse any old parts except the gauge, all was frozen together and or wrong size. The stand pipe for the pressure switch was clean. I adjusted the switch so far the spring was not being touched, i could not make it closer than 30 psi swing, so i replaced it.

    The new system which runs 40/60 has much better pressure and runs far less. Even with the larger tank it only takes about 55 seconds to fill from 40 to 60 psi. I see a csv in my future. I still need to recover from the cost of brass! The water hammer is significantly reduced as well.

    I also took advantage of this time and re hung my well pipe. I chose to use pipe insulation and 1.5" plastic hangers. I can barely hear the hum now, and can no longer hear it upstairs at all.

    Thanks for all your help.
    Chris
  18. Reach4

    Reach4 Active Member

    Messages:
    1,895
    Location:
    IL
    Did you install a new pump?
  19. cpowers

    cpowers New Member

    Messages:
    8
    Location:
    indiana
    No. I guess not everything.
  20. craigpump

    craigpump Member

    Messages:
    850
    Location:
    ct
    Should have put in a larger tank. Fewer and longer pump cycles equals extended motor life.
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