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The last 10 posts

Saturday, May 5th 2012, 1:46pm

by Central Irrigation

I would start by lowering your largest nozzles first. Change any 3's to 2's, and 2's to 1.5's. It may not be possible in your situation, but keeping matched precip. rates is important.

Saturday, May 5th 2012, 1:40pm

by johnstra

I didn't know I could shut the flow off on my heads (RB 5000 Plus). So I experimented a bit by shutting off the flow to all but 2 heads. Quite a difference... the droplet pattern out of the heads is much more what I expect to see - good even distribution. I then turned the flow back on one head at a time. Once I got up to 5 heads running the droplet pattern was pretty poor - more of a pencil stream coming out. I still get 27' or so but the distribution is poor.

All of that was with the nozzles that are currently in the heads.

So I'm going to replace them all w/ 1.5s and hopefully that will do the trick.


Saturday, May 5th 2012, 1:02pm

by Central Irrigation

Assuming you have no leaks in that zone, you will see dramtic improvement.

Saturday, May 5th 2012, 12:14pm

by johnstra

Yeah, I just checked that zone that isn't popping up... The nozzles add up to 13.5 GPM. They are all Rainbird 5000s.

So if I replace all the nozzles with 1.5 GPM, will the zone do ok?


Saturday, May 5th 2012, 10:10am

by wsommariva

6 at 3 GPM equals 18, too much for your 12 gpm. Some rotors have inserts that you change out for the gpm you need.

Saturday, May 5th 2012, 10:01am

by johnstra

Yes, what I'm calling the break-up screw is the radius adjustment screw.

I tested flow rate this morning twice. My system has a valve on the unregulated piping used for the sprinkler so it should be accurate. I get about 11.75 GPM.

I'll check the nozzles in a little while. I'm pretty sure they are all 2-3 GPM nozzles.

So is one thing to try replacing all the nozzles to meet my GPM? If I go with 1.5 GPM nozzles on the 6-head zones will I get better performance?


Saturday, May 5th 2012, 7:51am

by Central Irrigation

Why would they regulate a home that has static 45psi?
At any rate, the system branches off before the regulator, so the regulator isn't a factor. I'm more concerned with the size piping that exits the house. If they continued out of the house with 3/4", then the flow for the system should have been designed closer to 9-10gpm. 5-6 rotors per zone seems excessive for a 3/4" supply. I would calculate the zone's GPM recquirement before going any further. Look at the nozzle of each rotor and add up the numbers.

Saturday, May 5th 2012, 7:49am

by Wet_Boots

Don't go removing pressure regulators. Street pressures in Colorado neighborhoods can be off the charts, because of the elevations they have. One could attempt to adjust a regulator to bring up the outlet pressure a bit.

Saturday, May 5th 2012, 6:53am

by wsommariva

What is the break up screw - radius adjustment on the rotor of a screw on the valve?

Pressure regulator? Maybe it's bad. Maybe remove it and see what happens.

Also check psi again where the water exits the water meter, in the early AM with no other water running. Check gpm with a 5 gallon bucket and second hand.

Also, pics will help.

Saturday, May 5th 2012, 1:03am

by johnstra

Help with existing system

I've owned my home for a couple of years now and I'd like to get a handle on my sprinkler system. I have spotty coverage and several good sized dry spots.

I have about 2/3 acre (basically flat) to water. I live in Colorado so wind and evaporation rates are important

Let me state what I think the problem is and hopefully you guys can jump in and start me on the road to recovery...

I don't know a lot about the main lines. I do know they are 1" and that I have 12 zones, each with 5-6 rotor heads. The heads are a mix of brands and nozzles (Orbit and Rain Bird). They are all 3/4" housings. Last year I fiddled with the "break up" screws to try to get better coverage but I only made things worse. This year I've done more research and I've reset all my heads so the "break up" screws are out of the stream. I do have head-to-head coverage (head spacing is 24'-30') but I do not have square or triangular configurations that give optimal overlap - that's one problem. The other bigger problem is water pressure. My static pressure is 45 PSI. I measured at one of ports on the the anti-siphon valve. I have not calculated pressure loss yet but using the same gauge in the same port, I've observed that my pressure is around 15-18 PSI while the system is operating. I'm pretty sure the pressure is marginal at best for my rotor heads. One zone will not "pop-up" on it's own (I can push on a partially open head and get it running) and the other zones function but I suspect the pattern is bad due to low pressure.

My water supply is a 3/4" PEX line and the sprinkler system is fed off of the main line before the pressure regulator. I haven't measured GPM yet.

I'm willing to dig up and replace heads and/or replace nozzles and I'll add a booster pump if it'll help, but I don't have any interest in adding heads/zones.

I'm looking forward to your suggestions.

Thanks in advance for your help.