If one beings with 35 psi at the beginning, and 2200' of 2" schedule 40 pvc, with a "net" 20' drop, what would the psi of the water coming out be?
TIA
If memory serves me correctly, it's about .44 psi per vertical foot. If by "net drop" you mean 20' of head it would mean the pressure is 'bout 8.8 psi greater.
Depends on if the water is flowing or not. If the water is static then the pressure would be as Paden says about 8.6 psi greater. If the water is flowing then there is friction loss along the pipe and the more flow the greater the loss until all the available head (or pressure) is used up where the pressure at the end of the pipe would be zero (atmospheric) as it leaves the pipe. If the outflow is restricted through an orifice or valve then the pressure would be higher upstream from the valve but still zero in the atmosphere as the extra pressure is wasted via the velocity head in the outflow stream v^2/2g.
If your question refers to the pressure after a "net" 20 feet loss where the 20 feet equals the net of the friction loss and elevation change the the pressure would be 35 - 20/2.31 or about 26.34 psi.
> If memory serves me correctly, it's about .44 psi per vertical foot.
Yes about. I remember 1 foot head = 0.433 psi. There is going to be some friction loss depending on the route that the 2200 feet of pipe takes. Would have to get my old text books out for that one.
> Depends on if the water is flowing or not. If the water is static then the pressure would be as Paden says about 8.6 psi greater. If the water is flowing then there is friction loss along the pipe and the more flow the greater the loss until all the available head (or pressure) is used up where the pressure at the end of the pipe would be zero (atmospheric) as it leaves the pipe. If the outflow is restricted through an orifice or valve then the pressure would be higher upstream from the valve but still zero in the atmosphere as the extra pressure is wasted via the velocity head in the outflow stream v^2/2g.
>
> If your question refers to the pressure after a "net" 20 feet loss where the 20 feet equals the net of the friction loss and elevation change the the pressure would be 35 - 20/2.31 or about 26.34 psi.
I understood the math to equal that if I dropped in elevation, then pressure would go up, so I would think that the increase in pressure, from elevation, is 8.6 psi. However, the friction loss is what concerned me. After further review, it would seem, and I "measured" my GPM at the house filling a 5 gallon bucket a few times to be 15 GPM. The tables I found indicated roughly 0.2 psi/100 ft of pipe in a 2" pipe of drop, so over 2200 feet, I would lose 4.4 psi, for a total net gain after elevation drop and drag to be 4.3 psi.
DISCLAIMER: I have not, nor have I ever stayed at a Holiday Inn Express, nor have I played an engineer on TV, hence my questions. I just wanted to have someone check myself.
We are about to build a house on the back side of 70 acres I own and if the drop was too much, then we were going to drill a well. However, it would seem as I would gain some, or remain static, which is fine with me. We live at the bottom of a mountain and the 6" line that runs along the road has plenty of pressure.
Thanks guys!
That's what I came up with also. Thanks!
That was what concerned me also, and I came up with a loss of 4.4 psi along the route.
building a house in the middle of your hunting spot? I'm guessing Mrs. Morgan picked the house location? 🙂
0 PSI For The Water Coming Out
The pressure in the pipe is a different question.
Paul in PA
What really bites in when the friction loss is so high that the water has to go back uphill.:-D
Shawn
Yup, and the boy ain't happy about it messin up his deer hunting either. 🙂
Isn't that called the Chuck Norris factor?
Shawn
well. at least that far back you can sit on the porch nekkid if you want to (when the kids are gone).
