Question
I currently have 3 zones controlling the water to my lawn.  

I would like to add on to Zone 2 and know how to do the plumbing and where I want to connect into the existing 1/2 inch pipe which has currently 12 -- 3 gallon (max) per minute RainBird 32sa rotors running off of it.

The Community I live in provides the water through the irrigation ponds and I am not sure what the PSI is but it is very good for the existing number of sprinklers.

Would appreciate any advice on how I can determine how many more rotors I can attach without lowering the pressure significantly ?

Thanks

Answer
Nick,
you dont have 12 heads hooked up to a 1/2' pipe. i cant see that. You may have found a pipe that feeds 1-2 heads that is 1/2". It is fed by a bigger pipe that reduces down to 1/2" i would have to think.you cant get 36 gpm thru 1/2" 12x3=36
you shold be able to hook 1 additional head to the 1/2" if it seems like the pressure is good. Jim