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Saturday, June 19th 2021, 11:38am

Spray nozzles reduced spray range and weak pop-up

Hi all, Im a first time poster. I hope someone can point me in the right direction.

I have a Hunter XCORE 8 zone controller with 7 zones, 4 lawn, 3 drip shrubs. I'm on irrigation/secondary city water supply (separate from house water) I measured 100psi at the filter just after the city meter. High, I assume because I am downhill of most of the city. So I installed a pressure controller ( range 45-75 psi). This created my 'situation'.

One lawn zone has 26 rainbird popup spray nozzles (HEVAN 8,10,15's). I know, way too many heads on a zone, but thats what the builders guy installed and before everything worked fine.... quick head popup, full extension and hard/mist uniform spray from the nozzles. After installing the pressure valve, this zone is having troubles:
- it takes a minute or 2 for the heads to popup. a couple heads only pop up 3/4 of the way
- some heads spray uniform 'cones', some are 'ragged'
- some heads are spraying less than normal, for example a 10' 360 sprays about 6', a 15' 360 sprays about 10'

I opened the pressure reducers all the way counterclockwise from the preset setting. The supply after the filter now reads 65psi. it helped a little. My assumption is I have a pressure psi or flow gpm issue?

I'd really appreciate any troubleshooting suggestions and things I should try to diagnose and solve. I think splitting the zone in two is way too expensive... and destructive.

One thought is to replace the HEVAN spray nozzles with the new MP Rotor nozzles. They are said to use much less flow gpm. But at close to $10 retail, 26 heads is ~$250. And I don't know if it would work???




Posts: 2,601

Location: USA


Saturday, June 19th 2021, 5:30pm

Just take the pressure regulator back out. 100 lbs is fine. I've worked on hundred of systems with pressure over 100.
You could always get a regulator that goes from 75 to 150 lbs.
I'm assuming that you have pressure reducers on the drip lines.

To increase the pressure on the regulator you should turn the bolt clockwise. If you take that locking nut off you might get 80 lbs out of it.


Sunday, June 20th 2021, 2:52pm

Thanks MrFixIt!

I'll try removing the locking nut and get up to 80 psi.

The drip zones do not have pressure reducers. Should I get them? Are they part of the zone controller?

Thank you everyone!



Posts: 2,601

Location: USA


Sunday, June 20th 2021, 9:42pm

You'll need one per drip zone. Install it right after the valve.
Rainbird 30 lbs
Dig 25 lbs.

I already know that you'll ask me if 25 lbs is enough. Depends how big the drip zone is and what kind of emitters you're using. It should be fine in most cases.


Monday, June 21st 2021, 6:40pm


Got the pressure regulator turned up a bit. Pressure gauge is showing 85 psi off the main filter.

Better, but a couple heads are still only popping up 1/2 to 3/4 of the way. I'm going to try to find an adapter to measure the pressure at one of the heads on this zone.



Posts: 2,601

Location: USA


Monday, June 21st 2021, 9:33pm

You might want to look into Toro's precision nozzles. They use about 35% less water.
You really have too many heads on one zone. But I've cured low flow zones with these nozzles.
They have to run longer because they use less water.
They come in male and female so make sure you get the right ones.
toro nozzles
Here's about what they cost


Sunday, June 27th 2021, 3:19pm

So I finally got all the fittings to put the pressure gauge on one of the heads. Only reads 10PSI!! So I presume I have a pressure problem not a flow rate problem.

Pressure at the incoming filter by the road shows 95psi after the new pressure regulator. I'm confused.

Is there a way to measure pressure at the zone controller? I have the flow rate 'screw' turned all the way clockwise, which should be max flow. I don't see any wet/swampy spots indicating a leak. only 10psi would mean a pretty big leak, right?

Any suggestions on what to try next?
Thanks again!


Friday, July 9th 2021, 7:58am

I capped all 26 heads and measured pressure at one of the heads.... 62psi. Pretty goof right? But down from 95psi at the filter by the incoming valve from the street (secondary irrigation supply).

Has I open each spray head, everything looks fine until I have about 5 heads left to open up. That's when pressure drops and 1/2 dozen heads drop halfway.

Any thoughts on what's happening or what to try next?



Supreme Member

Posts: 5,381

Location: Metro NYC


Friday, July 9th 2021, 3:28pm

Maybe explore the 95 psi to 62 psi drop in greater detail? That isn't something that "just happens" - is there a pressure reducing valve in the circuit?


Saturday, July 10th 2021, 10:05am

Thanks for the thought to explore the 95psi at the filter to 62psi at one of the heads. There are no pressure reducers at the Hunter zone control valves.

I did discover a small leak (drizzle) at one head's funny hose elbow screw in fitting to the pvc supply. About 6 oz of water in 12 minutes. Maybe this was causing some of the pressure drop? I'll fix to day and retest pressure at the head.

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