piping algebra

tim wheat

ok...my customer has asked me a question and my mind wont let me figure it out...help please.....how many gallons of water would be in a 500' run of 2" copper pipe. please help me and tell me how to figure because im going crazy..thanks in advance...

jerry scharf

and the answer is

Siggy's software says it's 82.32 gallons for 500' of 2" type M copper.

There are published tables that show the gallons per 100' of any type of pipe. It's not just the 2", you need to get the exact ID of the exact type of pipe.

The geometry goes as follows: Volume of a cylinder is pi*r^2*h, but you need to watch for unit. 3.14*1*1 gives you the cross section in inches, then divide by 144 to get to square feet. Multiply this by 500 to get the cubic feet, then multiply by 7.48 to convert to gallons.

jerry

Mike T., Swampeast MO

Won't give you the numbers, but here's one way to do it...

Find the INSIDE diameter of the pipe and divide by two (the radius).

Find the area of a cross section of the pipe using 3.14 * radius ^ 2 --- (pi * radius squared).

If your radius was in inches this number is ALSO the CUBIC inches contained in one inch of the pipe. SO, multiply times 12 to get the volume contained in 1 foot of the pipe.

Then multiply times the number of feet and you'll have the final answer.

steve_40

volume of water in pipe

1. determine the x-section area of the inside of the pipe in square feet:

area =(pi*d^2)/4
=pi*((inside dia,inches/12)^2)/4

area for this example =3.1415*((2/12)^2)/4 =.021817 square feet

The key here is to convert diameter in inches to diameter in feet by dividing 2 inches by 12

2. Multiply the area in square feet times the length of the pipe in feet to get the volume in cubic feet,
or for this example: (500 ft)* 0.021817 sq ft= 10.90831 cubic feet

3. To convert cubic feet to gallons multiply the volume in cubic feet by 7.48,or for this example 7.48*10.90831=81.59 gallons

I chose to keep all units in feet for the calculations, but you could just as well keep all units in inches and then convert cubic inches to gallons. (there are many units converters on the Web)

flange

soirry, stopped doing those types of equations a long time ago. right about the time my apprenticeship ended. now I look it up in the tables. there are tables out there for everything, thats why you should keep every book you've ever come across regarding the trade.

DanHolohan

Once The Library is up,

we can include a chart that shows the capacity of pipes.

Billy_3

81.6 gallons

Diameter squared times 500 times .0408 gives you the gallons

Mark J Strawcutter

Mental exercise can be fun

I needed to cut a cradle in a piece of 1/8 aluminum to hold some 4in pvc. If the cradle were at right angles to the pipe it would be easy - cut a half-circle.

However, in this case it was at about a 30deg angle meaning it would be eliptical in shape.

One approach would be cut a scrap piece of pipe at the desire angle, put it against the aluminum and trace it.

But I happened to mention it to a math prof over coffee and he quickly derive a formula for a given pipe diameter and angle. I actually followed about half of what he did :-)

He asked me for the diameter and angle, and later that day dropped off some nice templates plotted using a math program he had. Two versions - one if I wanted to cut square to the plate, one if the cuts would be paralell to the pipe.

Mark

Mark J Strawcutter

Another one - orienteering

Friend of mine back in the early '70s was in ROTC in college and they were doing map reading/orienteering. One of the classroom exercises involved using a map, protractor and ruler to "start at point A, head Xdeg for so many miles, turn to heading Y for so far" etc and see how close you could end up to the correct ending point.

My friend was a physics major. He sat there with his sliderule and added each vector. At the end he had the resultant vector which he used to find the endpoint from the starting point in a single "hop". Really annoyed the instructors :-)

Mark

K.Black

piping math

A good book that I use is called "The pipefitters and pipe welders handbook". You may not use all of it but it's good to know it's there. It's by Thomas W. Frankland about 10-15$ good luck and stay safe.

Jacob Myron_12

Pipe math

The easiest formula to remember is Diameter squared times .7854 time the legnth of the pipe.

It is also the easiest to use on a calculator.

Jake