Drip Irrigation

 I installed drip irrigation and need some help with a problem.

I have (from faucet) backflow preventer, filter, pressure regular, hose
thread to 1/2" poly tubing.

The 1/2 polytubing is the distribution and runs about 80 ft. There are about
30 places where I have 1/4 dripline coming off and running to plants. Each
run of 1/4 is 4 ft max. The dripline is rated to 30psi and I used a 25 PSI
regulator.

So, turn on the water and instead of the 1/4 drip line dripping - it sprays
water 3 ft in the air.

I change to a 15PSI regulator - same deal, water sprays a little less but
still shooting a stream and not dripping.

I change to a 10PSI regulator- same deal.

What have I done wrong, why is this stuff spraying and not dripping?

Thanks for any help.

 Zook wrote:

You need an "emmiter" at the end of the drip lines.

BTW, you can put a globe valve after the regulator to drop the pressure
and adjust the flow rate without having to change the regulator.  A
small gate valve also works well, even thought the valve says to only
operate fully-open or fully-closed.

Bob

 
sorry, should have said - the dripline has pressure compensating emitters
every 12 inches.

 Zook wrote:

Then the pressure is still too high.  (I can't remember what pressure I
used way back when -- I think it was about 7 psi, achieved with a 15 psi
regulator followed by a partially open gate valve.)  Try putting a valve
between your regulator and your main distribution line and adjust it
down until the water drips out.

You can also turn the drip-line over so it sprays down.

The manufacturer of the drip hose should have a recommended pressure range.

Bob

 

Sounds like a 1/4" soaker line.  And, actually, those aren't Pressure
compensating emitters.  Pressure Compensating emitters sit either at the
end of a 1/4" line or in the 1/2" distribution line; they have a barbed
fitting on only one side, the other one is smooth.  From what you
describe, those are regular 1/2 gallon per hour inline emitters.  And,
yes, they *do* sorta spray out rather than drip and I don't think the PSI
matters a whit.

What I've done to sort of control the spray is to put either the stake
holding the line in front of the hole in the emitter to interrupt the
spray.  The water then drips down the stake and into the ground where it
should go.

As far as I know, the only way to get them to actually drip is to remove
them and replace as the diagram here:


BEFORE:
     O = Emitters
   --- = 1/4" line                

----O----O----O----O----O----O----(end)

AFTER:

    O    O    O    O    O    O    <--Emitters
    |    |    |    |    |    |    <--Small length of 1/4" line
----+----+----+----+----+----+    <--1/4" line
                                  + = Barbed T Fitting


But that's a lot of work.  Either try to arrange the spray to where you
want it to go or stick something solid in front of the hole and in the
path of the spray.

--Bryan

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