Pipe size vs flow rate

[Nathan A. Smith]

Hi,

I have been very confused over the relationship between flow rate and
pipe/tube size. So I thought I would ask the group to see if anyone could
explain it.

For the sake of this discussion -- let's eliminate the pump (just assume a
pump that is constant and it rated at 1000 gph at 1 ft lift). Let's also
eliminate friction over distance (assume distance is "short" enough that
it become negelagable).

Thus let's just look at what the effect of going from 1/2" tubing to 3/4"
would have (for example). Let's also consider the situation of going from
3/4" to 1/2" back to 3/4" (again, let's not worry about distance -- at
this point)


Thanks for the info

Nasa

[~ jan JJsPond.us]

I'm not sure exactly what kind of answer you're looking for, but as I got
help here when researching something for the KHA program, so shall you. I
should have saved the one that helped the most. Dang! But I went to google
and typed in Flow Rate Chart Pipe Size and came up with:
http://eesc.orst.edu/AgComWebFile/EdMat/PNW290.pdf

Page 2 has a pretty good chart on pipe sizes versus gpm flows. Of course a
pipe under pressure can flow faster than gravity, so we compensate by
making our gravity fed pipe size bigger. Do note that if you currently have
a 2" pipe flowing at 50 gpm, a second 2" will only give you another 50 gpm
or 100 gpm total, whereas replacing the 2" with one 3" will give you 110
gpm, or better 4" gives 200 gpm. Pressure and friction do play a big part.
~ jan

>On Sat, 07 Aug 2004 19:34:31 -0600, "Nathan A. Smith" > wrote:

>I have been very confused over the relationship between flow rate and
>pipe/tube size. So I thought I would ask the group to see if anyone could
>explain it.
>
>For the sake of this discussion -- let's eliminate the pump (just assume a
>pump that is constant and it rated at 1000 gph at 1 ft lift). Let's also
>eliminate friction over distance (assume distance is "short" enough that
>it become negelagable).
>
>Thus let's just look at what the effect of going from 1/2" tubing to 3/4"
>would have (for example). Let's also consider the situation of going from
>3/4" to 1/2" back to 3/4" (again, let's not worry about distance -- at
>this point)
>
>
>Thanks for the info
>
>Nasa

~Power to the Porg, Flow On!~

[chagoi]

Found this site a couple of weeks ago. very comprehensive listing of
info. Details all the little things that effect how our pond filter
systems perform.


http://www.advancedaquarist.com/issues/jan2003/featurejp.htm


--
/\/\ike
Chagoi
http://ourkoipond.com

Nathan A. Smith wrote:
> Hi,
>
> I have been very confused over the relationship between flow rate and
> pipe/tube size. So I thought I would ask the group to see if anyone could
> explain it.
>
> For the sake of this discussion -- let's eliminate the pump (just assume a
> pump that is constant and it rated at 1000 gph at 1 ft lift). Let's also
> eliminate friction over distance (assume distance is "short" enough that
> it become negelagable).
>
> Thus let's just look at what the effect of going from 1/2" tubing to 3/4"
> would have (for example). Let's also consider the situation of going from
> 3/4" to 1/2" back to 3/4" (again, let's not worry about distance -- at
> this point)
>
>
> Thanks for the info
>
> Nasa


--
/\/\ike
Chagoi
http://ourkoipond.com

[Nathan A. Smith]

On Sun, 08 Aug 2004 12:34:12 -0400, chagoi wrote:

>
> Found this site a couple of weeks ago. very comprehensive listing of
> info. Details all the little things that effect how our pond filter
> systems perform.
>
>
> http://www.advancedaquarist.com/issues/jan2003/featurejp.htm


Wow,

Great website -- thanks

Nasa
>
>
> --
> /\/\ike
> Chagoi
> http://ourkoipond.com
>
> Nathan A. Smith wrote:
>> Hi,
>>
>> I have been very confused over the relationship between flow rate and
>> pipe/tube size. So I thought I would ask the group to see if anyone could
>> explain it.
>>
>> For the sake of this discussion -- let's eliminate the pump (just assume a
>> pump that is constant and it rated at 1000 gph at 1 ft lift). Let's also
>> eliminate friction over distance (assume distance is "short" enough that
>> it become negelagable).
>>
>> Thus let's just look at what the effect of going from 1/2" tubing to 3/4"
>> would have (for example). Let's also consider the situation of going from
>> 3/4" to 1/2" back to 3/4" (again, let's not worry about distance -- at
>> this point)
>>
>>
>> Thanks for the info
>>
>> Nasa