Bubbler - Water Height

Discussion in 'Water Features' started by tadpole, Apr 14, 2012.

  1. tadpole

    tadpole LawnSite Bronze Member
    Posts: 1,216

    I usually avoid decorative water features, but I had to replace the pump in an urn bubbler for an existing customer. I installed a 500 gph mag drive which, as best that I could determine, is the standard size for this type of water feature. The customer would like the water to have a greater height than the approx 2 -3 " that it presently has.
    My question is: Instead of moving up to the next larger size pump (700 gph). could I instead place a cap on the existing 1/2" stand pipe and drill a smaller than 1/2" hole to increase the PSI? How much smaller hole would I need to drill to get about 6" in water height?
     
  2. 1idejim

    1idejim LawnSite Fanatic
    Posts: 8,866

    you could possibly try using a 1/2" extender repair coupling or inside coupling. reverse the extender. this will close the opening to about 3/8" i believe

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  3. tadpole

    tadpole LawnSite Bronze Member
    Posts: 1,216

    Thanks Jim. That may work, if I can find an extender coupling locally.
     
  4. 1idejim

    1idejim LawnSite Fanatic
    Posts: 8,866

    most irrigation suppliers can have them next day and they're not that expensive. i stock a few of each size for leak repairs.

    if you can' get one contact me, i may have one in the shop and i can mail it to you.
     
  5. 1idejim

    1idejim LawnSite Fanatic
    Posts: 8,866

    i have a few 1/2". if you can't find them contact me :)

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  6. tadpole

    tadpole LawnSite Bronze Member
    Posts: 1,216

    I appreciate the offer, Jim, but wouldn't a 1/2" cap drilled with a 3/8" hole accomplish the same results? You irrigation guys deal with PSI all the time, us Water Feature guys are usually only concerned with Flow Rate.
     
  7. 1idejim

    1idejim LawnSite Fanatic
    Posts: 8,866

    depends if the cap were flat or convex on the inside. if the cap is convex then you stand a chance of avoiding hydraulic cavitation turbulence. i feel that the smooth surface of the extender and the inch long neck may prevent directional changes that may be undesirable.

    i might be making more of this than there is but i am thinking that you want to raise the water column with the least amount of distortion.
     
  8. Ric

    Ric LawnSite Fanatic
    Posts: 11,946

    .


    Are you sure restricting flow will increase the PSI the desired amount?? This will work on a POSITIVE displacement pump. However most of these submersible pond pumps are CENTRIFUGAL and are limited in PSI but not GPM.

    Remember the GPM rating on Pumps is OPEN FLOW with NO back pressure. Add just a touch of back pressure and Flow can drop by half very quick. My point being Do you have the Right pump??

    At the price of a Screw on PVC Cap I would buy several. Of course I would Drill each different sizes. By installing a slip to IP thread you can quickly change caps until you find the correct size.

    BTW I have made my own fountain nozzles with multiply sprays with just a PVC cap and a drill. Yes it is a trail and error process.


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  9. tadpole

    tadpole LawnSite Bronze Member
    Posts: 1,216

    The final solution was using a 1/2 inch cap with a 3/8 inch hole drilled dead center. Keywords DEAD CENTER, a little off center and you no longer have a vertical water plume. In this case, the type of pump did not matter. This was a 700 gph mag drive. The 3/8" hole increased the height of the water plume four-fold, which was too high. This was easily corrected by reducing the flow rate.
    I would still like to know the formula for determining the effect of flow restriction on PSI. I know there is a formula, engineers have one for everything.
     
  10. 1idejim

    1idejim LawnSite Fanatic
    Posts: 8,866

    i was sure that extender would have worked. bummer. there is a formula for gpm @ psi static using sized mains but it works on large pipe only i gvess. these gauges are common for use on hydrants for fire depts. see pollard water
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