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danm

New Member

1

Monday, August 20th 2012, 11:46pm

Pressure regulator need and placement

I think I've found 80% of my answer in this forum. Thanks! I think I need a regulator, but I'm not sure where to put it.

I have 75 static PSI. My flow at a spigot with a 3/4" feed was 12gpm. The sprinkler is fed by a 1" main line connected within a couple feet of the house meter. My rotors are misting like crazy and have poor coverage in the midsection of the spray. I have Hunter I-20 Ulras, three or four per zone, with nozzles rated 2gpm @ 45psi. I also have a few zones with 4 Hunter Pro Sprays. They are working well. From what I've read, and my experience, pressure appears too high. I know its not in the 100's, but what else would cause such misting? I don't have the adjustment screw obstructing the nozzle hole or anything like that. I thought about going to 3gpm nozzles, but I don't want to affect the rest of the house too much. I have a Wilkins 720A backflow preventer on the main line.

I'd like to install a pressure regulator and turn it down until the misting stops, if someone agrees, unless someone has a better idea. Is this right?

Then, if it is right, is there any problem installing the regulator a couple feet downstream from the backflow preventer? I thought I read upstream is preferred, but my preventer is installed right outside the house, nestled between my deck's floor joists. It would be a mess to move. I do have a couple feet of copper inside the house, but I assume the regulator makes some noise.

Your thoughts?

Wet_Boots

Supreme Member

Posts: 4,088

Location: Metro NYC

2

Tuesday, August 21st 2012, 11:36am

Why not adjust the flow controls on the zone valves? Or maybe install a master valve with a pressure regulator on it. The master valve route can be less expensive, because you aren't buying a big chunk of brass. It also will maintain any needed flow and pressure better than a stand-alone PRV.

danm

New Member

3

Tuesday, August 21st 2012, 4:06pm

Thanks for the quick response! I have PGV-100 valves, no flow control. But that makes me wonder if its easier to swap out the rotor zones' valves with PGV-101s, possibly just swapping the guts if I can confirm the bodies are the same.

That may add up to the same $ as a pressure regulator on the mainline, but give me more control. If I do end up with a mainline pressure regulator, do you see a problem installing it a couple feet downstream of the backflow preventer?

Wet_Boots

Supreme Member

Posts: 4,088

Location: Metro NYC

4

Tuesday, August 21st 2012, 6:24pm

I couldn't really recommend a standard PRV being installed after the system is designed and installed, because a PRV won't be wide open for full flow until it's dropping the pressure about 50 psi, and I have serious doubts whether the system would still be working at all.

mrfixit

Moderator

Posts: 1,464

Location: USA

5

Tuesday, August 21st 2012, 8:10pm

I doubt it if by going to a larger nozzle if it will affect your house at all..

danm

New Member

6

Tuesday, August 21st 2012, 8:35pm

Thank you both. I see two simple, cheap options to try. I can open up the nozzles and see how it impacts the house. And I can upgrade the valves on the rotor zones. Odds are I can just replace the top halves of my valves, leaving the connections in place. Thanks again!

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