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heschlie

New Member

1

Monday, April 15th 2013, 8:13pm

Sprinkler nozzle not spraying to listed distances

Hi All,

I recently purchased and installed a system, or at least finished one zone so far, I purchased the Rainbird HE-VAN12 nozzles and I seem to be only getting ~9ft not 12ft radius. I checked each of the heads for contaminates, shut off all but 2 heads, and I'm still sitting with only about 9ft of distance. Some more info on the system:

At the valves I am getting (Rainbird 100-ASVF):
42psi
15gpm
Measured from an adjacent valve.

I am using 3/4" sch40 PVC for the laterals, at a maximum distance of 70ft. I am at a loss here, should I rerun with bigger pipe? From what I understand (which may be wrong) with the sch40 I should be getting ~10gpm of flow still, and down to 2 heads I should only be using about 4.72gpm. I was thinking of opening up the valve and seeing if there is anything clogging it, but I'm at a loss otherwise.

Thanks for any help!
-Stephen

Central Irrigation

Supreme Member

Posts: 352

Location: Central Minnesota

2

Tuesday, April 16th 2013, 11:04am

Few thingds to check....
1. Are the radius screws on the spray nozzles closed at all?
2. Is the valve that runs these spray heads a Flow Control model?
3. If the answer to 2. is yes....is the flow control fully open?

heschlie

New Member

3

Tuesday, April 16th 2013, 1:31pm

Few thingds to check....
1. Are the radius screws on the spray nozzles closed at all?
2. Is the valve that runs these spray heads a Flow Control model?
3. If the answer to 2. is yes....is the flow control fully open?
1 - They are fully opened
2 - Yep it is a flow control valve
3 - Yes the flow control is completely open

There is noting in the body of the sprinkler that is adjustable correct? I am using the Rainbird 1804 SAM series.

Central Irrigation

Supreme Member

Posts: 352

Location: Central Minnesota

4

Tuesday, April 16th 2013, 2:41pm

There is a check valve in that head, but if all heads are spraying equally, then that probably isn't an issue. The VAN nozzles do spray water in a flatter trajectory than standard nozzles, but you should still get close to 12'. Are the nozzles misting or fogging as they spray? I'm trying to get a visual on how they are working. I have seen, that if the heads are buried to low in the ground, they won't spray as far. Are they trying to spray up an incline?

heschlie

New Member

5

Tuesday, April 16th 2013, 4:33pm

There is a slight slope, maybe 2" drop per 10' but even the one on higher ground going downhill I'm still only seeing just above 9'. I took apart the valve to check if anything was clogging it, but it looked clean. I also turned back on the other 4 heads and could not see a visible difference in spray.

They are not misting or fogging, I can shoot a video if it will help. At this point, since I am not seeing any difference when adding the other heads back, I was thinking of respacing the heads and adding one more to fill in the dry spots, as I really am at a loss here and adding one head is much easier than rerunning the pipe and hoping the problem goes away (which at this point I would be surprised if it did) from lack of flow.

Thanks much for your help so far
:)

Wet_Boots

Supreme Member

Posts: 4,028

Location: Metro NYC

6

Tuesday, April 16th 2013, 5:13pm

the generic "what did the amateur do wrong" answer is that the water supply was over-estimated, and the sprinklers on a zone aren't receiving enough flow or pressure ~ modern technology supplies some miracle cures with spray nozzles being replaceable by MP Rotators

heschlie

New Member

7

Tuesday, April 16th 2013, 5:56pm

Thanks for the vote of confidence there wet_boots, could you please elaborate for the amateur did wrong with this calculations? I did the bucket test for GPM at the valve, and also hooked a gauge up to get the PSI from the same valve, which the numbers are stated above. I was also worried that I had run into a flow problem but I turned the system down to 2 spray heads being active with no visible change between that and 6 heads (a flow change from 10.06gpm to 4.74gpm)

I don't mean to sound overly snarky, but I would honestly like to know where I could have done a much better job here, this isn't my first system implementation, but I certainly am not a pro, and would like to know where I went wrong.



(no actual edit performed here - just a site hiccup)

This post has been edited 2 times, last edit by "Wet_Boots" (Apr 16th 2013, 9:01pm)


Central Irrigation

Supreme Member

Posts: 352

Location: Central Minnesota

8

Tuesday, April 16th 2013, 7:38pm

It very well could be the nozzle itself. I have no experience with the HE nozzle. You could try a different nozzle and see what thar does.

Wet_Boots

Supreme Member

Posts: 4,028

Location: Metro NYC

9

Tuesday, April 16th 2013, 8:51pm

Thanks for the vote of confidence there wet_boots, could you please elaborate for the amateur did wrong with this calculations? I did the bucket test for GPM at the valve, and also hooked a gauge up to get the PSI from the same valve, which the numbers are stated above. I was also worried that I had run into a flow problem but I turned the system down to 2 spray heads being active with no visible change between that and 6 heads (a flow change from 10.06gpm to 4.74gpm)

I don't mean to sound overly snarky, but I would honestly like to know where I could have done a much better job here, this isn't my first system implementation, but I certainly am not a pro, and would like to know where I went wrong.


A pro "bucket test" would measure flow and pressure simultaneously. There are special gauge assemblies made for this purpose. Separate measurements can be misleading. In any event, if you have a static (no flow) water pressure of 42 psi, you are in fringe territory. By simple addition of pressure-loss numbers, you might be lucky to have 30 psi at the nozzles.

I would look at MP Rotator nozzles, either the 1000 or 2000 series.

Also, is there a pressure-reducing valve in the supply?

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