How can I get more pressure from my gravity water system?

Question

Have about a 60 ft drop from my spring to the house and about a 600 ft.run with inch and a half poly pipe.I get around 25lb psi.If I increased the pipe size to say 4 inch would that give me more psi. Booster pump out of the question as I am off the grid.

Answer 1

If you increase the entire run (outlet included) you would get more volume, not more pressure. I'm not a plumber or a physicist, but I do remember a relation V1P1=V2P2, so if your "transmission" is a 4 inch pipe that reduces to a smaller size, say 2 inch, then pi X 2" squared X 25 psi = pi X 1" squared X P2, and P2 must then be larger, and the volume per unit of time would be smaller. You can find the volume for, say a ten foot length of tubing for each side, and get the new pressure.

Answer 2

Gravity Flow Water System

Answer 3

For the best answers, search on this site https://shorturl.im/ayhb7

You can buy water pressure test gauges from places like Home Depot. However, a gravity fed system would have a large water tank on the roof or in the attic and the water pressure in the outlet would depend on the difference in height between the tap and the water tank. If you use your garden hose and point straight up, it can't go any higher than the height of that tank and would probably be a bit short of it. You'd contact a plumber to change your plumbing. You may have low water pressure but I doubt that it's from being gravity fed and indeed the solution to low water pressure from the utilities is to put up a water tank, pump the water up there and be gravity fed.

Answer 4

Revised (I misread the current pipe length and diameter).

The static pressure will be the same with any pipe - 14 psi every 32 feet of drop, but the pressure at the input to an *open* valve increases with a bigger pipe, and that's what really matters. Basically, to increase flow, you need to decrease impedance. This means increasing the tube size and/or switching to high flow ball valves at both ends. They have a throat diameter equal to pipe they fit. The biggest bang for the buck would be changing the valves.

Answer 5

First, I'm guessing you have a valve at the house and are measuring water pressure on the upstream (spring) side of the valve right with the valve closed right? Then you open the valve and the flowrate is poor and you wonder why?

With the valve closed, the pressure on the upstream side of the valve is dependant only on the height of the spring relative to the valve. 60 ft. of pressure = 720 inches water = 720 x .03612 psi / in = 26 psi. pretty close to your 25 psi.

With the valve open you observe pressure losses due to the friction of the water flowing through your 600 ft of horizontal pipe so that your pressure on the upstream side of the valve is <<26 psi.

Flow through a valve can be calculated by

Flowrate = Cv x (dP)^.5
and typical Cv factors are say 250 for a 1 1/2" ball valve
and dP = upstream pressure - downstream pressure (zero if it's open to the atmosphere)

the pressure drop through the pipe can be estimated by

dP = k x L/D x d/2 x w^2
where k = coefficient of friction
L = length of pipe, D = diameter of pipe
d = density of fluid
w = flowrate

anyway the dP across the valve depends on the pressure loss in the pipe. for larger values of D, dP through pipe will decrease, pressure on upstream side of valve will increase and flow through the valve will increase. for smaller velocities, dP will also decrease. same effect.

so in summary......
if you go from 1.5" to 4" pipe, your increasing D by 2.6 and decreasing dP through the pipe by a factor of 2.6. but since flowrate through the valve = k x (dP)^.5, you should see an increase in flow of about 1.6 times for the same valve.....

Answer 6

To increasee the diameter will not increas the pressure. If u have all things turned off and get 35 lb per sq. in. 1.5 poly pipe should support any 2 foists turned on at a time. The vertical height will increase your pressure. U should get about .5 lb per vertical height.

Answer 7

(60ft x 0.433psi/ft = 26psi. this pressure WILL NOT change with larger pipe diameter but, with such a long run, a bigger diameter will decrease the friction and give more volume available up to your house valve but, from there your back to normal plumbing sizes.
I don't believe it will improve matters one bit though.
If your spring is feeding a head tank, the only way to get an increase is with a higher tank.
Then again, 10 feet more will only give 4.33 psi extra..

And, once again, the thumb's down man knows better.

Answer 8

There are two things you can do to increase the pressure, raise the height of the water tank or raise the level of the water in the tank. If there is no room in the tank to raise the level than install a tank that will allow a higher level. Pressure is produced by the weight of water and the only way to increase the weight of the water is to increase the level.

Answer 9

With a bigger pipe you'll get better flow rate, but the static pressure will be the same. Hook up a booster pump to a pedal powered generator.

Answer 10

Increasing the pipe size will help some. You can get UP TO .43 psi per foot of drop. Smaller pipe resists water flow.
_____________________________
KrazyKyngeKorny (Krazy, not stupid)
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯