Calculating Water Volume in Different Sizes of Pipe

Calculate? Eh?

Why not measure it with a flowmeter?

...or measure the change in level in a tank over time, when the water is flowing?

Clarify the quesion of you want a clear answer.

A man is flying in a hot air balloon and realizes he is lost. He reduces height and spots a man down below. He lowers the balloon further and shouts: "Excuse me, can you tell me where I am?"
The man below says: "Yes, you're in a hot air balloon, hovering 30 feet above this field."
You must be an engineer" says the balloonist.
"I am" replies the man. "How did you know."
"Well," says the balloonist, "everything you have told me is technically correct, but it's no use to anyone."
The man below says "you must be in management."
"I am" replies the balloonist, "but how did you know?"
"Well," says the man, "you don't know where you are, or where you're going, but you expect me to be able to help. You're in the same position you were before we met, but now it's my fault."

A little more detail is required -

1. Are you asking for recommended maximum volume (velocity) through pipes?
2. Do you have an existing system and you are wondering the current volumes?
1. What sizes of pipe are you dealing with?
2. What length/material of pipe do you have?
3. Is the system gravity fed or do you have a pump?
1. Elevations?
2. Do you have a pump curve?
3. Do you at least have some pressure readings?
3. ..............
4. ...............

Please search for other threads on this topic, as there has been a lot of discussion already:

For example:

http://cr4.globalspec.com/thread/21081#comment240540

You could also try a portable ultrasound flowmeter that attaches externally to your pipe.

There are many manufacturers of these devices (or you could possibly have an engineering consultant help you).

I have heard mixed reviews of the accuracies of these units though, one point to note is that they may not work well on clean/potable water - they usually require some solids within the fluid.

I worked a little with one at my old company and we were able to get pretty accurate numbers with one (I forgot the model) as compared to inline flowmeters that were already installed.

http://www.sensorsmag.com/articles/1097/flow1097/main.shtml

You seem to only be concerned about the relative flow under the same conditions for different sizes op pipe.

Equal velocities is quite easy but I suppose you may be interested in equal losses.

If you take the Blasius formula for smooth pipes (that was the first one I could lay my hands on now) you will notice that after the constants like Reynolds number, length and pressure has been canceled out the relation in flow can be written as

V1²/D1 = V2²/D2

take a math class,there are formulas for all calculations. Dah

calculating the water volume in differant pipes sizes

1. calculate internal dia of differant pipes
2. calculate cross section areas at differant pipes
3. calculate the volume at differant pipes
4. we know the density of water
5. now we can calculate the volume of water

use the formula:

Q=AV Where Q represents volume

A is the sectional area of the pipe

V is the velocity of water passing through the pipe