[SEL] O.T. O.T. Need Help On Water Flow Problem

[Bob Willman]

	I would think that very very small holes at the 16 locations so that
the water flow from each is a very small percentage of the flow in the main
pipe so as to maintain constant pressure throughout the system. As it is the
pressure drops after each discharge hole. You could start with a larger
diameter pipe up front and reduce the diameter after each opening which, I
think, is the accepted method.
	If all the holes are already drilled and the system is level, I
would try turning all the discharge holes to the top of the pipe and use a
very slow flow rate in order to fill the entire pipe and let it slowly run
out over the pipe to keep the flow rate slow but hopefully stabilize the
pressure along the whole length.  


Bob Willman
Bowling Green, Ohio
The Eagle's Anvil
WB8NQW

-----Original Message-----
From: sel-bounces at lists.stationary-engine.com
[mailto:sel-bounces at lists.stationary-engine.com] On Behalf Of
paulmaples at sbcglobal.net
Sent: Tuesday, June 02, 2009 10:42 PM
To: sel at lists.stationary-engine.com
Subject: [SEL] O.T. O.T. Need Help On Water Flow Problem

Folks I need to apply equal amounts of water at 16 locations around a
rectangular square made if 1/2" pvc pipe. (8 locations down each side and
none on ends)

The length of each side of the rectangle is 111" and the ends are 27".

http://s52.photobucket.com/albums/g36/wheelterrapin/?action=view&current=dia
gram.jpg

One man told me to drill 1/4" holes at each of the 16 locations but I argued
with him that the first few 1/4" holes located closest to the input of the
water would get more water than the rest and he said it would not.....well
they did. The first 4 holes on each side of the PVC closest to the inlet of
the water shot out streams of water about 4" long and the last holes, the
ones furthest away from the inlet of the water just dribbled water.

I am only drilling holes down the length of the rectangle and none on the
ends. The PVC pipe size is 1/2" and as stated above the length of each side
is 111" long.

I use a 5/8" water hose (it only has a 1/2" bore size) to bring water to the
inlet of the rectangle. The bore size of the 1/2" pvc pipe is .485", almost
1/2".

The water flow rate is 5 gpm per minute coming out of the end of the 5/8
hose.

Can someone tell me how to plumb the rectangle in order to achieve an equal
flow of water at each of the 16 drilled hole outlets. I would assume I will
have to start out with small holes closest to the inlet and gradually get
bigger towards the end opposite the inlet of the water. I just want the
water to dribble out and not shoot out in streams and I need, as close as I
can get it, equal amounts coming out at each of the 16 drilled locations.

At each of these 16 locations there is a tomato plant. I am trying to
calculate how long to leave the water on in order to be able to supply 1" of
water to each plant as the tomato plants require 1" of water weekly and more
during the hot months.

I will appreciate any and all help on this.

Thanks,

Paul
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