Homestead mailing list

[Rob <becida AT comcast.net>]

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Date: Mon, 15 Jan 2001 09:55:09 -0800
From: tvoivozhd <tvoivozd AT roanoke.infi.net>
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To: "Homestead mailing list" <homestead AT listserv.unc.edu>
Subject: Re: market-farming digest/fwd: Irrigation System
Reply-To: "Homestead mailing list" <homestead AT listserv.unc.edu>



FranksFarm AT aol.com wrote:

tvoivozhd---you've evidently got more flow than you need, but with 5000 feet 
to
traverse you need to break up the irrigation system into manageable
segments---I'd say 1000 feet or less to avoid a lot of line loss in small
diameter irrigation tubing. It is generally cheapest to use one and one half 
or
two inch plastic tubing for headers and one inch for laterals.  I have used
three-quarter inch and found it too small..

If you made such a division, what is the fall in the creek across each 1000
foot?  If sufficient to provide desired pressure and flow from five hydraulic
rams, each feeding a storage tank (or small excavated lake) fifty or more feet
above the irrigated area, you should have enough pressure for spray heads, 
more
than enough for subsurface irrigation (leaky hose)---"Irrigro" works on 5 psi.

To avoid damage to hydraulic ram pumps, you need to anchor them well, and get
them out of the flood plain.  At the head of each 1000 foot creek 
segment, build
a concrete collection tank, with a removable screen on top, over which is a
removable pipe-grid to fend off larger debris, limbs, rocks etc.

The collection tank will have one or more pipe outlets cast into the 
downstream
wall, to which is fitted the drive line leading to the ram.  If 
desired, you can
use multiple lines leading to a ram to economize on tubing cost.
Murphy's law dictates that you design for floods and freezes.  Rams 
won't freeze
if the flow doesn't stop, but it is a good idea to plan on it 
stopping when it is
least wanted or expected, ergo, put them in an insulated house.

So clay or sand does not accumulate in the low points of the drive-line, try 
to
keep it descending at an even rate from collector basin to ram with no
significant dips in elevation.  It is desirable to bury the line in 
whole or part
to protect it----renting a Ditchwitch.  Where it crosses a depression 
it will be
necessary to support it on a pylon, and insulate it with split 
polyurethane foam
insulating cover---tape the seam and cover that with four-inch black 
corrugated
drainpipe against UV and mechanical damage.  All this is a lot of work, but a
whole lot less than cleaning out reoccuring line plugs.  It is easier 
to keep mud
out of the line in the first place by screening well at the intake and keeping
dips out of the supply line.

It is also a good idea to filter the ram output to spray heads or 
subsurface hose
to avoid the annoying necessity of cleaning out lines to them when 
clogging stops
operation.

If you have fields lying in different directions from any one ram, 
use a multiple
valve station to alternatively direct the flow to them.

If you kept any of my old postings on high head, low head rams, they are a lot
cheaper to make than to buy, though the old Rife rams will live forever. For
serious, long-term use rams, made of steel and bronze are preferable 
to PVC---the
latter are more suited for gardening.