Figuring how much water in a pipe

[Lynn Coleman]

Hi all,

A while back there was a discussion about various water tanks and a pvc tank under the floor for a tear, might have been something MadJack had done, not sure. Anyway, I'm thinking about building a passive solar hot water heater to place on the roof of my TTT. But as I was researching solar water heaters, I started to wonder how much pipe would be needed for five gallons of water.

I'm thinking in terms of 3/4" copper pipes. How many feet would I need to get 5 gallons?

I'm also thinking, it might just be a lot easier to purchase one of those camping five gallon bags at Wally World for a few bucks rather than make an actual solar tank.

Anyway, if it isn't too much trouble would one of you, who knows this kind of formul, be able to figure how many feet of pipe I would need to equal five gallons?

Thanks in advance,
Lynn

[ARKPAT]

BrianB
Teardrop Master


Joined: 17 Oct 2004
Posts: 253
Location: Casina, Italy
Posted: Fri Feb 04, 2005 3:27 pm Post subject:

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I was using the V=Pi*R2h formula. Using that, there should be 2412.75 cubic inches in a 4"x4' tube. With a gallon of water taking up 231 cubic inches, it works itself out to about 10 gallons.

Then again, I liked Geometry in school so much I took it twice.

Thanks for the compliment, Dave. I call it "ode to Roly."

I'm not sure if this is what you where looking for but it looks right.



Pat

[Steve_Cox]

Lynn,

About 82 feet, I think. But.... maybe not. Algebra class was 45 years ago.

Solar showers work well, used one a lot when I lived on my sailboat. They are pretty heavy when full. Here's one for $10. Solar Shower

[dovaka]

i believe it works out to 5.3 cubic inches per foot of pipe and there are 231 cubic inches of water per gallon making each gallon use 43.5' of pipe and 5 gallons would be 217'

it also has been awhile since i did math like that so i may be totally wrong but you would be better off using small 1/4" copper pipe and having a holding tank and just pumping the water threw the small copper

[Keith B]

Okay... I think I can remember my geometry:.....
Volume of a circle.
P=3.14 (pie)
r;squared=radius squared or (1/2) the distance across the inside diameter multiplied by itself.
l=length
There are roughly 231 cubic inches in a gallon of water.

Formula: p*(r)(r)*l=cubic volume.........cubic volume/231=gallons

Here's the formula (example) for a 4" pipe, 4' long:
3.14x4 (radius is 2", radius squared is 2x2)x4x12=602.88cu inches.
602.88/231=2.61 gallons

Here's the formula (example for a 6" pipe 7' long:
3.14x9x7x12=2373.84 cu in.
2373.84/231=10.28 gallons

I was acutally thinking about mounting a 6" sewer piper x 5' long under my frame by the axle for fresh water:
3.14x9x5x12=1695.60/231=7.34 gallons (same as an "aquatainer)

DISCLAIMER: I'm an idiot so this formula may be incorrect, but I'm "fairly" confident.

[Ira]

I did the math, and you need 3 million feet of 3" pipe to hold 3 quarts.

But let me double check that--I may have accidentlaly moved a decimal point.

[steve wolverton]

I did the math, and you need 3 million feet of 3" pipe to hold 3 quarts.

But let me double check that--I may have accidentlaly moved a decimal point.

No, 3 million feet of 3" pipe sounds about right. Probably get a discount for bulk purchase too.

[Keith B]

Actually, if you consider the heat in KS, the teardrop itself gets pretty hot during the day, so if you have good rubber on the windows and doors you could just stick a hose in the fantastic fan and fill the entire TD for a nice big hot water supply....hmmm, lets see, a 5' TD w/ 8' of interior (bed) space....this is of course if the interior is "round" inside... consider not everything is square I'll just assume it's more round than straight

3.14x900x8x12=271296.00/231=1174.44 gallons... that outa do it.

[Alphacarina]

i believe it works out to 5.3 cubic inches per foot of pipe and there are 231 cubic inches of water per gallon making each gallon use 43.5' of pipe and 5 gallons would be 217'

I get the same number as you did - 5 gallons of water would out an extra 30 pounds ot so on the roof of a tear . . . . not the best thing for the center of gravity - Not to mention that the 217' of copper pipe would probably weigh another 50 or 60 pounds

A plastic 'Solar Shower' bag makes lots more sense - I've used those on sailboats too and they heat water pretty quickly and are the original 'member' of the 'K.I.S.S' club

Don

[Lynn Coleman]

Actually, if you consider the heat in KS, the teardrop itself gets pretty hot during the day, so if you have good rubber on the windows and doors you could just stick a hose in the fantastic fan and fill the entire TD for a nice big hot water supply....hmmm, lets see, a 5' TD w/ 8' of interior (bed) space....this is of course if the interior is "round" inside... consider not everything is square I'll just assume it's more round than straight

3.14x900x8x12=271296.00/231=1174.44 gallons... that outa do it.

[Lynn Coleman]

A plastic 'Solar Shower' bag makes lots more sense - I've used those on sailboats too and they heat water pretty quickly and are the original 'member' of the 'K.I.S.S' club
Don

Thanks all for your responses. I agree a solar shower bag is the smartest move. I started to think that way when I started to think just how many feet of pipe would I need.

Hey you can't say I don't bring some humor to the forum.

Lynn

[bug_power]

if you want to make you something you can really use, get that solar shower and make a mount for a hook to hang it on. I was building an aluminum prototype that was callapsible for the beach called the surfer shower. It would fold up into a towel bag.

[teachu]

http://www.watertanks.com/calc.asp

[Laredo]

Cub Scout Day Camp Tipi Project, circa 1998 -- this can be modified to make your own shower tent/ potti tent/ dressing room tent:

Butterick 4251 sewing pattern has directions for building a tipi that's 80'' high by 72'' bottom circumference, with a 65'' interior clearance.

If you make the poles 14'' longer and omit the drilled-through, string-between-beads frame closure (you may like that better than my method below, though), you can make one that's 7'x'6 1/2' with a 6' interior clearance. (Yes, cut the fabric -- if you're cutting; we draped tarps with binder's twine through the grommets, but we were going for a "rustic" look; you can use cable ties for convenience -- as much longer as you cut the PVC poles, plus 1/2'' for hemming.)

We used 1 1/4'' pipe that we wrapped with camo tape; instead of drilling it and stringing it between beads, we glued T-fittings at each end of each pole. Then we laid the poles out on the ground, and at the "top" we put a 6'' connecting pipe between each pair. If I'd known about them I'd've used some of these fittings instead of the lashing technique we did use: http://www.pvcplans.com/fivewaysm.jpg, but since the lashing was part of one of the knots badges, it was OK.

I still have that pattern. Hmm. Wonder how hard it would be to repeat the trick with shock-cord Wal-Mart tent poles and some ripstop fabric?

[madjack]

http://www.watertanks.com/calc.asp

...that is the link I had posted earlier about finding the volume of a tank...unfortunately, in this case, figuring out what percentage in decimals, 3/4" is in comparison to a foot was just more math than I wanted to deal with ....
madjack