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 320' of line and low flow, whats the fix?
Author: 8Up (SC)

Hi everyone, I recently installed 320' of line from my well to my shop. The line goes up a 4' grade from the well for the first 160 feet and down about a 2' slope for the last 160 feet. I ran 1 1/4 for the first 100' then 1' for the next 100' then 1/2" the rest of the way ~ 120'. I am getting very low flow but it will build pressure if I put my thumb over the end. I have two questions. Was I fundamentally wrong putting in the different diameter lines? AND, if I replace the 1/2" with 1" will that solve the problem or do I need a stronger well pump? Thanks in advance.

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 Re: 320' of line and low flow, whats the fix?
Author: North Carolina Plumber (NC)

1/2" is too small for an underground service of that length, but you should still have plenty of pressure, just a low volume. Can you put a gauge on the end of the pipe to check the pressure ?

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 Re: 320' of line and low flow, whats the fix?
Author: hj (AZ)

He DOES have pressure when he puts his finger over the end of the pipe, just no volume which is what you would expect from 120' of 1/2", especially since we do not know what the material is.

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 Re: 320' of line and low flow, whats the fix?
Author: stuckinlodi (MO)

You might want to check the total head spec on your well pump, see what it is capable of. Then calculate the head you will have in that size pipe over that distance. There are also friction losses over that distance to take into account. Your local well company can help with this. If you are noodling around with it be sure to keep an eye on your pump motor, make sure it isn't overheating. That many feet of pipe full of water, some of it uphill, will have a certain surprising weight the pump has to push, luckily some of the run is downhill. Cost is a factor on any project like this but you probably should have used larger pipe for the entire length.



Edited 3 times.

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 Re: 320' of line and low flow, whats the fix?
Author: m & m (MD)

The 1/2" was your undoing. Another less costly option would be to install a pressure tank in your shop (WX 252, WX350) and allow it to store the pressure. A check valve would be a must.

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 Re: 320' of line and low flow, whats the fix?
Author: 8Up (SC)

I should have mentioned that the 1/2 inch is PCV sch40. looks like I will be replacing that with 1", not a big deal. I was hoping because of the 2'fall that it would be enough but obviously not. I will have to also go check the specs on the pump and report back because I doubt I will be able to make heads or tails of it. Thank you for your responses they are all very helpful.

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 Re: 320' of line and low flow, whats the fix?
Author: stuckinlodi (MO)

Here are a couple of good articles to read, explains a lot of the basics in an easy to understand way:

[www.irrigationtutorials.com]

[www.irrigationtutorials.com]



Edited 2 times.

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 Re: 320' of line and low flow, whats the fix?
Author: hj (AZ)

The 2' fall will add about a pound to the PSI, which is not enough to overcome the loss due to the small pipe size.

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