SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

inputed your calcuations wrong?

What you think your results beat the 1000's of hours of testing of pipe designers/creators?
Just stick with the flow charts

Not really

Your garden hose has much more friction loss then pvc.. That's why it's not used.
Your hose bib can only supply soo much water
And your single impact head is only using 2-3 gpm.

Your not going to have one sprinkler head per zone are you?

Since you know your going to be installing your sprinkler system. Install your back flow assembly either at the point of connection after your water meter or the point of connection that enters your house. Get your flow test done and your dynamic psi measurement done too

What freezing weather? You have yet to fill in the info that posts your location.

The location of a backflow preventer depends upon the type of backflow preventer you are going to use.

The question of which backflow preventer you are going to use starts by determining what is required by your local building codes. Local codes vary and can be as specific as "you must use company A, part number B" or as loose as "any industry standard backflow preventer".

The most typical options (listed in order of effectiveness) are RPZ, PBA, and DCBA (what ever those mean). If you use a DCBA, it can be installed in the same room as your meter. But many people question the use of DCBA in irrigation (it offers the least protection) and therefore may not be allowed by local building codes. If you have to use an RPZ or PBA, those will pretty much have to be installed out-doors above ground.

On the west side of the cascades 95% of back flows are DCVA's ( double check valve assembly) . These one's don't drip water.