Sprnklers

   / Sprnklers #1  

Rio_Grande

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I just ran some sprinklers for our garden. There are 5 total and if I run more than 2 the other 3 only spray about 3 feet but the first two run great. I am running it off of a tractor mounted pto pump and tanked water fertilizer mix. The pump is capable of 22 GPM at 300 psi running 1200 rpm max. My tractor only runs about 600 rpm wide open.

Can I reduce the sprinkler nozzle size and get the other 3 running? Would love to run 7 at once!
 
   / Sprnklers #2  
Pipe size and design is important. Tell me about your pipe sizing. Do you drop down in size as you get further out to the end of the line?
 
   / Sprnklers
  • Thread Starter
#3  
No it is 1 inch all the way out.
 
   / Sprnklers #4  
Rio_Grande said:
No it is 1 inch all the way out.

That is your problem. How long is the run? You likely have too large of pipe but for sure you need to size down approx half way down the run. If you were to start over, and not saying you should, you would use 3/4" then go down to 1/2" about half way on the length of the run. If you have T's off the main line then you would use 1/2" there also. You will see a significant difference than what you have now.
 
   / Sprnklers
  • Thread Starter
#5  
That is doable. They are garden hoses I can go buy a few and of that works I will change out the other side.

Thanks for the input

As for length I have a 200 ish foot run to one garden and 100 to the other
 
   / Sprnklers #6  
Rio_Grande said:
That is doable. They are garden hoses I can go buy a few and of that works I will change out the other side.

Thanks for the input

As for length I have a 200 ish foot run to one garden and 100 to the other

Explain a bit more...is your entire line hoses or does a hose connects to a PVC sprinkler line? A garden hose is typically 1/2" or 5/8" so if that is the case then you are up-sizing to a 1" line you have just reduced your pressure. You need to increase or maintain your pressure as you continue down line. You lose pressure by distance and each sprinkler head.
 
   / Sprnklers #7  
I'm just glad I'm not the only one that does this. It works pretty good. I'm just running one sprinkler right now.
 

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   / Sprnklers #8  
I just ran some sprinklers for our garden. There are 5 total and if I run more than 2 the other 3 only spray about 3 feet but the first two run great. I am running it off of a tractor mounted pto pump and tanked water fertilizer mix. The pump is capable of 22 GPM at 300 psi running 1200 rpm max. My tractor only runs about 600 rpm wide open.



Can I reduce the sprinkler nozzle size and get the other 3 running? Would love to run 7 at once!



If you are running 7 heads at 3 GPM each, you are at your max.

For equal pressure, the supply should be in the center. Same distance to each head will provide same pressure/distance. More pressure and GPM's = more distance

You are only able to get that high pressure if you have resistance to the flow.

I am not sure your hoses or sprinkler heads are usable up to more than 60 psi

SKD 40 is good up to about 320 psi.
 
   / Sprnklers #9  
Rather than fiddle with piping size, you can change the orifice size on the sprinkler heads. Most models have interchangeable nozzles letting you control aim and/or flow rate. Ultimately, a good system will have all the heads setup for proper balance to maximize use of the available gpm and pressure. I have even gone as far as adjusting head orifice size for the sweep angle of rotors, so that all heads in a zone put out the same precipitation rate.

In order to use the head/nozzle to balance flow rate and pressure, the supply line diameter has to be much much larger than the orifice diameter, so that the head is the definitive pressure loss. Balancing the piping layout is also important in long runs, so that you do not introduce biases due to frictional pressure losses. It's not a big deal in short runs.
 
   / Sprnklers #10  
Like s219 said, you need to match your sprinklers to your pump. Running at half RPM will mean different things for different pump styles but you've got what you got. You also don't want to eat up spraying potential with loss in your lines, so definitely don't make them smaller between sprinklers. The issue you have is that your first sprinklers are too big for your pump and are using most of your capacity. The two ways to fix this are smaller nozzles or some other restriction BETWEEN the main and the first sprinklers, such as a valve you can throttle, or a smaller pipe, again just from the main to the sprinkler, you don't want a smaller main anywhere. Keep in mind you may get your pump to run 7 sprinklers but you might not like their performance.
 
 
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