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

Quoted from "HooKooDooKu"

If you KNOW you are going to install irrigation and you KNOW where you're going to tap into the main line, if you need really accurate data, then tap the line and do the tests from there. Otherwise, my personal preference is to make sure the system is designed for a whole lot less water that what your system can produce (I still want to be able to take a shower while the irrigation system is on).

As for the Class 200 pipe, I don't see any reason to use it for a DIY install. The Sch40 PVC (in 1/2" to 1" size) is cheap, so you're not gaining a huge cost savings, and gaining stronger pipe to better withstand rocks that might be in your backfill or other problems. If you are looking at the Class 200 because it has a largers inside diameter, you're already sort of constrained by the 3/4" pipe comming from the meter. Upsizing to 1" Sch40 PVC from the 3/4" supply should be just fine.

If i Tap into a 3/4 supply line, the use a 3/4 DCVA, then up size to 1'valves and manifold pipes, then go to 1-1/4 from the valves to the heads, then back down to 3/4 outlets at my tees, with half inch funny pipe back to 3/4 inlets to sprinklers! Will it work? ALL SCHEDULE 40

Quoted from "Mitchgo"

Actually pvc prices have skyrocketed this year. The prices are quite different now.

Most professionals stick with 1" as a standard for small-midsize residential systems. reduce back to 3/4 half way through your zone to save costs.
I'm worried about pressure loss, i have 3 zones, each one 200 ft, i will have about 45psi after the valve loss! Add the pipe and i see to much loss for 1'' not to mention 3/4 or am i wrong?

Quoted from "HooKooDooKu"

Quoted

I'm worried about pressure loss, i have 3 zones, each one 200 ft, i will have about 45psi after the valve loss! Add the pipe and i see to much loss for 1'' not to mention 3/4 or am i wrong?

If you design for a flow rate of 10gpm, then you will lose about 5 psi in your 200ft of 1" pipe. If you design for a flow rate of 15gpm, you will lose about 10 psi in you 200ft of 1" pipe.

So if you are only using spray heads, you have a little extra pressure to work with while keeping to the cheapear 1" pipe.

But if you are attempting to use rotars and trying to throw a distance of 40', you'll need at least 40psi at the heads and you'll need larger pipe.

Now if you use the MPRotators that Mitchgo referenced (I like them, they are more expensive than standard nozzles, but easy to design with because they require less flow), and you don't need to throw more than 30', then you look to be right on target if you try to design for a flow of about 10gpm per zone (+/-), and just use how ever many zones you need to keep the flow rate near 10gpm per zone, you'll be fine with 1" pipe.

The qestion becomes which is cheaper, more zones with 1" pipe, or fewer zones with more expensive 1-1/4" pipe.