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

 

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

 

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

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.

 

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

 

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.

 

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.

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.

 

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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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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.

 

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.

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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Jim-
Isn't there a formula that you irrigation gurus use on pipe size reduction to maintain a certain psi. I know on long runs the pipe size must be reduced periodically.

 

Jim-
Isn't there a formula that you irrigation gurus use on pipe size reduction to maintain a certain psi. I know on long runs the pipe size must be reduced periodically.

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Any good plumbing or irrigation Book will have FRICTION LOSS CHARTS FOR PIPE. Google FRICTION LOSS CHART FOR PIPE OR HOSE ETC. Hose will have more friction loss because it has more twists and turns etc.

As a one time Irrigation contractor I started sizing Pipe from the Farthermost point. As I came closer to my water source the Pipe size increased because I had more sprinklers on the line. The point of reducing pipe size is economic if you don't need 400 GPM at the far end.

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Any good plumbing or irrigation Book will have FRICTION LOSS CHARTS FOR PIPE. Google FRICTION LOSS CHART FOR PIPE OR HOSE ETC. Hose will have more friction loss because it has more twists and turns etc.

As a one time Irrigation contractor I started sizing Pipe from the Farthermost point. As I came closer to my water source the Pipe size increased because I had more sprinklers on the line. The point of reducing pipe size is economic if you don't need 400 GPM at the far end.

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Thanks Ric, but friction loss is not what I am referring to, although it may influence the answer.
An example of what I am wanting to be able to determine in future projects:
You have a 1" ID pipe through which is passing water at the rate of 500 gph at a pressure of 30 PSI. You reduce the pipe size to 3/4". What is the new PSI? What is the formula for arriving at this answer?

 

Thanks Ric, but friction loss is not what I am referring to, although it may influence the answer.
An example of what I am wanting to be able to determine in future projects:
You have a 1" ID pipe through which is passing water at the rate of 500 gph at a pressure of 30 PSI. You reduce the pipe size to 3/4". What is the new PSI? What is the formula for arriving at this answer?

There are Fountain pumps and there are transfer pump. Fountain Pumps will produce more pressure and less volume. The Manufacture should have pressure and spray height data on their website. Along with nozzles and light kits etc

My main point being, it is the type of pump that is the important factor. Only other thing I can tell you is Trail & Error on the pumps you are now using.

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There are Fountain pumps and there are transfer pump. Fountain Pumps will produce more pressure and less volume. The Manufacture should have pressure and spray height data on their website. Along with nozzles and light kits etc

My main point being, it is the type of pump that is the important factor. Only other thing I can tell you is Trail & Error on the pumps you are now using.

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All that I have found is what they call "feet of head pressure" which is listed under the various nozzle types to determine height of spray/plume or height and throw. Someone has to know how to convert this to PSI.

 

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Sorry I can't help you. I can only suggest to contact a Fountain pump manufacturer's technical dept and see if they can give to a formula.



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