Hi rati,

Hard to believe with the availability of PVC sch 40 pipe, that you can't find it in any big box hardware or irrigation supply store. It is much cheaper than copper and is inert in the soil. The pvc pipe is for your mainlines and polyethylene pipe for laterals with emitters attached. If you have to, order it on-line. Google drip irrigation installation.

That is too high a pressure for drip. There are in-line pressure regulators that you can buy. Pressure should be dropped to about 20-25 psi for drip. If you take the water off your house supply it should be about 50-55 psi. There are reducer for all sizes of pipe. If this is from a well use a good filter and pressure regulator with backflow preventer. GL Aloha

Thanks GL. What I meant is that the only existing water pipes near my backyard are 1/2" copper. Accessing the main line would involve ripping apart my new driveway and I don't want to do that. So I'm trying to figure out if a drip system would work if I hook it up to the 1/2" pipe. I'm planning to use a pressure regulator, but I thought the high pressure could help offset the fact that my flow is lower than what I would get from a 3/4" pipe. What do you think? thanks.

hi rati,

Nope. The factors that affect flow are diameter of pipe, length of the line, slope of line and type of material the pipe is made of. In a yard the lengths around the yard won't make much of a difference. Higher pressure helps the ability to have more irrigation outlet points or heads or emitters. Each outlet point robs the line of a little pressure, so there are only so many heads on a system with a certain pressure before you have to add zones. High pressure maximizes the number of heads per zone you can run. Flow also is used at each outlet and thus there are only so many heads you install before you use up the available flow. The emitters or heads are rated for gallons per hour for a given pressure. Add up all the head flows and make sure it is only about 3/4 of the flow you can deliver from the copper pipe. Measure the flow by filling up a five-gallon bucket and time the fill. Calculate gallons per hour or GPM. I would recommend 3/4" PVC mainline and 1/2 lateral with emitters connected. A 1" system is not much more expensive. Good Luck. (GL)
Aloha