The plumber's puzzle
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  1. #1
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    Default The plumber's puzzle

    If copper siding comes in sheets of 3ft x 3ft for $40 each, then what are the most economical dimensions for a rectangular tank to contain 1000 cubic feet?

  2. #2
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    Quote Originally Posted by jscpm View Post
    If copper siding comes in sheets of 3ft x 3ft for $40 each, then what are the most economical dimensions for a rectangular tank to contain 1000 cubic feet?
    Even though you have some rems, at a quick glance,. it would still appear that a 10x10x10 is still the most economical... as most of the rems can be re-used within the tank.

    Of course a 6x9x11.9 has very little remenant

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    water towers are round for a reason. the most economical tank self supporting, thus rouond. swimming pools are an example. Look at the extra work and materials needed to bolster the sides of a rectangular pool.

    unless your copper lining an existing frame.... but then you would not have asked about the shape. and designing a new and overly complex frame just to optimize liner use seems wastefull

    themost efficinet use of surface area/volume for a rectangle is a cube.

    but 10x10x10 is a big cube. and the outward pressure at the bottom of the tank will be 10 feet of head. 4.33 psi or 624 pounds per square foot. and it could really hurt if it burst.

    http://www.accontrols.com/documents/...WatertoPSI.pdf

    a 20x20x2.5 tall , or even larger and lower would make me feel safe.

  4. #4
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    Do you plan on just covering a tank with copper? For the money you're talking, that copper sheet would have to be about 0.015" thick or less.

    A sphere has the lowest surface area ratio to volume. You'd need a sphere with a radius of 6.204' (about 74.5"). That gives you a sphere with a surface area of about 484 square feet or about 54 sheets. I doubt that copper that thin would support itself on a 12 1/2 diameter sphere.

    Just make yourself a wood buck and start forming.
    JR

  5. #5
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    what is Copper siding?

    A 3x3' sheet of copper that costs $40 would have to be very thin. Way too thin for what you are proposing.

    A 3'x10' sheet of 16oz. copper runs over $300 last I checked, but prices always change

  6. #6
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    What do you have against rotationally molded tanks?

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    Maybe I'm off the mark here (or had too much bourbon), but I think this is a puzzle (maybe it was the title).

    If so, I think the rules should include:

    Can't bend, shape or cut the sheets.

    Find the least number of 3'x3' sheets that could be welded together, and hold >1000 cu.ft.

  9. #8
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    Default The plumbers puzzle

    Without going to a bunch of charts and things, I believe their is about 7.5 gallons of liquid in a cubic foot.
    Regards Walt.

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  11. #9
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    Default

    Does the tank require a top?


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