# eeked out another 8 volts on the hydro - Page 2

Posted by z on October 18, 2008, 1:26 am

thats an idea i'd never even considered.  one line for each jet.. woah

My setup now is a 2 inch 100 foot line that goes into 300 more feet of 1-
1/2, so I had always thought to just make the rest 2 inch.  But I could
add another one altogether.. and under low water just use the one.

nice!

yeah i might try that eventually

thanks man!

-zachary

Posted by BobG on October 18, 2008, 2:18 am

==========================
=====================
So the electrical analogy is: consider the 2" pipe as 100' of #12 wire
and the 1 1/2" pipe as 300' of #14 or whatever gauge has the same
ratio of cross sectional area. If I know the ohms per foot, I can calc
the total IR drop. Is this about the same as the pressure loss along
the 400' of pipe? Seems the water has to run thru the 1 1/2" pipe
faster, so it must have more frictional loss. What's the units of
water flow resistance?

Posted by Ken Maltby on October 18, 2008, 5:43 am

==============================================
So the electrical analogy is: consider the 2" pipe as 100' of #12 wire
and the 1 1/2" pipe as 300' of #14 or whatever gauge has the same
ratio of cross sectional area. If I know the ohms per foot, I can calc
the total IR drop. Is this about the same as the pressure loss along
the 400' of pipe? Seems the water has to run thru the 1 1/2" pipe
faster, so it must have more frictional loss. What's the units of
water flow resistance?

You could be lazy like me, and use the tables in the
"Pocket Ref" by Thomas J. Glover  Sequoia Publishing
ISBN 1-885071-00-0

It has a lot of other such data for water;
including:
Friction loss in pipe fittings

Horizontal pipe discharge ( easy way to get the GPM)

Nozzle Discharge  ( GPM for a given nozzle dia. @ a given
pressure)

and at least a half dozen more.

Sequoia Publishing, Inc.
P.O. Box 620820 Dept. 101
(303) 972-4167

http://www.bookfinder.com/dir/i/Pocket_Ref/1885071000/

Luck;
Ken

Posted by z on October 18, 2008, 6:36 am

I use this application to do the calculations.  You can try different
sized pipe and pressures to see what to expect

Posted by daestrom on October 18, 2008, 7:00 pm
BobG wrote:

Trouble with water flow is that the pressure drop usually follows flow
squared.  That is, double the flow and you have four times the pressure
drop.  Not the simple linear relationship of Ohm's law.

This means that for a given flow rate, the pressure drop is proportional to
1 / d^5.  So if you double the pipe diameter, you get 1/32 the pressure drop
if you somehow manage to keep the same flow.  So there's definitely
something to be said for going with larger pipe.

daestrom

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• Subject
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 Re: eeked out another 8 volts on the hydro Vaughn Simon 10-18-2008
 Re: eeked out another 8 volts on the hydro Vaughn Simon 10-20-2008
 Re: eeked out another 8 volts on the hydro Vaughn Simon 10-18-2008