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

Quoted from "heschlie"

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?

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.

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)

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

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

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?

Quoted from "Central Irrigation"

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.

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?

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