# Rain Bird R-VANs -too much irrigation!



## TheSwede (Jul 10, 2018)

So, I have a 8 ft by 24 ft area where I have put down 8 R-VANs, -the 8-14ft version in a head-to-head coverage square pattern. Thing is that it puts down way more water than I anticipated per hour -I measured it today and it puts down more than twice the amount of water compared to what is stated in the tech specs. Also, I find it very difficult to adjust the throw length down to 8ft. Could it be that the pressure is too high to this zone? I use the 1" Rain Bird DVF valves so I guess I can lower the flow to this fairly small zone (I have 26 gallons/minute flow and 65 PSI static pressure)?


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## g-man (Jun 15, 2017)

26gpm in 1in? That's unsafely high. Do you have the conversion correct?

Does the valve have a flow control? You might be able to reduce it that way? Are you using pressure regulated bodies?


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## TheSwede (Jul 10, 2018)

g-man said:


> 26gpm in 1in? That's unsafely high. Do you have the conversion correct?
> 
> Does the valve have a flow control? You might be able to reduce it that way? Are you using pressure regulated bodies?


26gpm is the max flow I get if i disconnect the manifold and measure the flow. The largest zone I have designed uses less than half of that. I do not use pressure regulated bodies. My engineering mind figured that if I get a valve with flow regulation I can regulate the flow and hence the pressue to the right level in the heads, provided I have large enough supply lines. But after today's late evening session, freezing my *** off slipping around in the mud with my crocks and sexy shorts, trying to force 8 heads into submission spraying 40 F water at insane rates and at the same time trying to regulate the flow without success I thought I'd ask here if it is normal to get like 2" of water in less than an hour from these heads in a square config...

So, tomorrow I'll try to turn down the flow from the valve and see if it makes any difference....


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## TheSwede (Jul 10, 2018)

TheSwede said:


> g-man said:
> 
> 
> > 26gpm in 1in? That's unsafely high. Do you have the conversion correct?
> ...


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## g-man (Jun 15, 2017)

I dont have experience with the r-vans. The spec calls for 0.67in/hr @ 55PSI. 2in/hr seems really high.


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## Ware (Jan 28, 2017)

@Rain Bird Corp is a member here. I bet they would be glad to offer you some guidance.


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## Ecks from Tex (Apr 26, 2018)

TheSwede said:


> So, I have a 8 ft by 24 ft area where I have put down 8 R-VANs, -the 8-14ft version in a head-to-head coverage square pattern. Thing is that it puts down way more water than I anticipated per hour -I measured it today and it puts down more than twice the amount of water compared to what is stated in the tech specs. Also, I find it very difficult to adjust the throw length down to 8ft. Could it be that the pressure is too high to this zone? I use the 1" Rain Bird DVF valves so I guess I can lower the flow to this fairly small zone (I have 26 gallons/minute flow and 65 PSI static pressure)?


I suspect your heads are fine and you need to regulate the pressure/flow and change your watering practices.

1. The recommended operating pressure is 45 psi so you need to control or otherwise regulate the flow of water. The highest pressure tolerance the R-van has is 55 psi. Moreover, unless you have the 360 head, you should not be exceeding 1 gpm to each head. The recommended gpm for a 270 degree head is .94 gpm at 45 psi.

2. The heads are meant to put down a lot of water quickly so that you can practice intermittent watering. You should adjust the spray times and make it such that you are watering in multiple short intervals over a period of hours rather than a continuous watering.


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## TheSwede (Jul 10, 2018)

g-man said:


> I dont have experience with the r-vans. The spec calls for 0.67in/hr @ 55PSI. 2in/hr seems really high.


Yes, that's what I thought! One of my neighbors who I managed to infect with the lawn care bug last year and also is installing irrigation lent me a T-coupling from Hunter that I could fit a pressure gage on to measure the pressure at the sprinkler head itself revealed that I had way to high pressure at the head. I adjusted the flow to get 45PSI (3.1 bar) and redid the measurement using the only straight sided vessel I could find at the time -one of my wifes rare vintage Iittala "Paratiisi" tea cups  . She would kill me if she knew I used them for measuring how much my irrigation system lays down, but this time I got away with it... . I ran the zone for 15 minutes and it was around 13mm (1/2") in the cup and frankly, the zone lays down a s**tload of water -way more than the soil can absorb.


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## TheSwede (Jul 10, 2018)

Ecks from Tex said:


> TheSwede said:
> 
> 
> > So, I have a 8 ft by 24 ft area where I have put down 8 R-VANs, -the 8-14ft version in a head-to-head coverage square pattern. Thing is that it puts down way more water than I anticipated per hour -I measured it today and it puts down more than twice the amount of water compared to what is stated in the tech specs. Also, I find it very difficult to adjust the throw length down to 8ft. Could it be that the pressure is too high to this zone? I use the 1" Rain Bird DVF valves so I guess I can lower the flow to this fairly small zone (I have 26 gallons/minute flow and 65 PSI static pressure)?
> ...


Thanks for the info -I'm a complete newbie when it comes to irrigation systems so I have a lot to figure out. It is just that my other zone that uses 5004 and MPR nozzles put down pretty much exactly the amount stated in the charts, and the R-VANs are supposedly matched to the MPRs when it comes to perspiration rate so I am a bit concerned with the big difference in perspiration between the 5004 and the R-VANs.

The strategy you suggest with several shorter cycles and some "soak time" in between will solve my problem if I can't adjust the heads to give the stated perspiration rate.


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## TheSwede (Jul 10, 2018)

Ware said:


> @Rain Bird Corp is a member here. I bet they would be glad to offer you some guidance.


Sure hope so!


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## g-man (Jun 15, 2017)

Can you go lower in psi? 2.5bar? It is still crazy high for 13mm in 15mm (52mm/hr)

Don't break the tea cups. She will not be happy. Get a can of sardines.


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## TheSwede (Jul 10, 2018)

g-man said:


> Can you go lower in psi? 2.5bar? It is still crazy high for 13mm in 15mm (52mm/hr)
> 
> Don't break the tea cups. She will not be happy. Get a can of sardines.


I can go lower, but at some point the heads will not rise up and spin properly. My thoughs right now is that I should go through head by head and make sure each one is only throwing 8 ft. It is really difficult to see the throw length when there aer so many heads on such a confined space. Then again, it is not the end of the world, I can arrange for a cycle and soak schedule. However, from a learning point of view it would be good to know what is going on here!


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## TheSwede (Jul 10, 2018)

g-man said:


> Don't break the tea cups. She will not be happy. Get a can of sardines.


Well, I was hoping the exclusive vintage tea cup might draw the attention away from the sorry state of my lawn right now.,,,when the lawn reno is done, I'll get you a photo of a sardine can on the lawn for comparison...


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## g-man (Jun 15, 2017)

Looking at the heads, it seems that you have less than 8ft (2.5m) between the heads too.


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## TheSwede (Jul 10, 2018)

g-man said:


> Looking at the heads, it seems that you have less than 8ft (2.5m) between the heads too.


The heads are spaced pretty much exactly 8ft apart in a square pattern. I've double checked and adjusted the throw lengths today but a thunderstorm hit before I got a chance to measure. I'll do a measurement as soon as the thunderstorm has passed.


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## TheSwede (Jul 10, 2018)

OK, so I redid the measurement after trying my best adjusting them to 8ft throw. I had them on for 15 minutes and measured in three spots. One in the center of the square pattern and one on each side. I got 9mm and 11mm in the center and one of the side ones which equals 1.5" per hour. The third one was 16mm, which equals 2.5". The pressure was measured to 45PSI.

For comparison, I ran the large zone with the 5004 with MPR nozzles (the beige 35 feet nozzles) for 30 minutes and the perspiration rate measured is exactly as stated (I got 8mm in 30 minutes which equals 0.6"/hr).

I don't know, but either my R-VANs are broken or Rain Bird is holding back information of how much water these things actually deliver when dialed down to 8 ft radius.


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## Movingshrub (Jun 12, 2017)

Any chance that you're getting the amount of water that would normally be applied over 14', spread over 8' instead? So, considering we are taking area of a circle, 3x the amount you would expect? I am not saying this is fact, just trying to think through causes.


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## Movingshrub (Jun 12, 2017)

I put out my irrigation gauges and ran my r-vans 18-24s, for 10 minutes. I am using the 30PRS pop ups, however, my pressure is 80psi. I don't expect a $10 pop up to perfectly regulate down to 30 psi so I'm sure it's higher than that. Anyways, I got about 0.10" inches of water with a ten minute run time. I put out ten gauges so I could also measure places with overlap.


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