# pvc pipe size question

Hi there:
Sorry for intruding but can I ask a question. Can someone tell me please how much water roughly will travel through PVC 40 pipe by gravity (no pump), if it's vertical (roughly) and only about 6 ft high? In a few different diameters? I've looked on the internet and I can only find tables of friction loss and tables of maximum flow rates. I just want to get an idea for an aquarium system that I'm building. i.e. with 1/2", 1", 1.5", etc.
I appreciate any and all help. Quietreef
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
"quietreef"
I don't think plumbers would know this. Try looking for "'alt.physics" or something.
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
On Sun, 06 Mar 2005 00:57:34 +0000, quietreef wrote:

The formula for figuring volume of a cylinder is 2 pi r squared times height.
In the case of 1/2" inch pipe 72 inches high that would be (2 x 3.14 x .25squared) x 72. Which would give you 28 1/4 cubic inches. 1 gallon(US) is 231 cubic inches. So that would give you .1223 of a gallon, or about a pint.
That's how much water it will hold. How much water will travel through the pipe depends on whether it will be at full volume for the pipe and how long a period of time you are looking at. For a 6' length of pipe, friction loss is minimal for an aquarium.
Are you asking how long for a certain amount of water, or how much water in a certain amount of time?
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Hi there:

I'm looking for rate. If the water is falling by gravity with no pump or back pressure, roughly, how many gallons/hour will I get in a 1/2" pipe or a 1" pipe, which I assume is 2X whatever the 1/2 number is. Now that you've laid it out so nicely, I should be able to figure it out, thanks.
quietreef
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>

You mixed up the formula. It is pi r squared NOT 2 pi r squared. 2 pi r is for circumference.
You need a different formula to figure out the flow rate anyway (but you willuse this calculation also). You need the pressure of the water. In a vertical pipe you get 1 PSI of pressure for every 2.33 feet of head (height). You'd be at about 2.5 PSI at 6' (without a calculator). I am still looking for this formula, but if will give you cuft/sec. Then you can use 7.48 gal/cuft of water to calculate gal/sec.
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
"Eric G."
Hey, by this time, he could have built the stupid thing, bought the pipe in several sizes, and timed it by himself.
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Yeah, I think I'll probably just do this. It's easy enough to time it myself, but thanks anyway.
Quietreef

<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>

I never said I was quick :-)
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
I have held off on this post because it is soo stupid. Fill the god damn tub and time it darining dont build a thing. There are groups dedicated to fish tank systems.

<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Be nice.....he may be making a home for Hots girl....Wanda !

<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>

## Site Timeline

• ### Help with Kitchen Drain- funny and sad story.

• - next thread in Plumbing Forum
• ### Plumbing a new bathroom

• - previous thread in Plumbing Forum
• ### Is turning off water to outside faucet at 20 degrees okay?

• - newest thread in Plumbing Forum
• ### Identify this bathtub fixture

• - last updated thread in Plumbing Forum
• ### OT:Yes there really are idiots this thick in the potteries.

• - the site's newest thread. Posted in UK Do-It-Yourself Forum
• ### The Witch Hunt Poll

• - the site's last updated thread. Posted in Home Repair
• Share To

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.