A common question asked is how many heads
can I put on a zone. In order to answer that we need to know what the available water is
at the source at a certain pressure. A bucket test is a good way to determine this. To perform
the bucket test you need to have an apparatus similar to this. We’re going to hook onto
a hose bib with a hose adapter. Then the next thing I have is a pressure gauge. After the
pressure gauge I have a shutoff valve and then a short piece of hose. What I’m going
to do is I’m going to open the hose bib up all the way. When that happens, I will have
zero pounds of pressure. I can’t operate a system on zero pounds of pressure, so I will
slowly shut off the valve. That will build up back pressure to simulate what the head
requires. In my example, I need 30 psi. Once I achieve that, I’m going to put the end of
the hose in a five-gallon bucket and I’m going to time how long it takes to fill up the bucket.
It took us 23 seconds to fill up our five-gallon bucket. Now to do the math we’re going to
take the five gallons divided by the 23 seconds, and that would give us gallons per second.
We want gallons per minute so we’re going to need to multiply that by 60. In our example
you’re going to get 13 gallons per minute. Now if I know I’m using a sprinkler head that
uses two gallons a minute, I can put six of those heads on a zone. You can find the products
that we use to perform this test at your local Ewing branch, or you can visit us online at
ewingirrigation.com.