Question
Hello there,

I have a small lawn about 40 ft by 15 feet and have renectly had an irrigation system installed.  The guy that installed it used 2 inch PVC pipe and about 15 rain bird popups.  The water for the system is drawn from a 10,000 gal tank by a 2hp pump through 2 inch pvc pipe.  There is a gate valve befoer the pump to control the flow of water to the sprinklers. Needless to say, when I water (even for 5 minutes) I use a huge amount of water from the tank.  Is there any way I can reduce the volume of water to the grass with the current setup?  Will a Pressure reducing valve or a feedback line to the tank help?

Pls advise, and I really appreciate the help!

Regards,

Kevin

Answer
Hey Kevin, basically each head will use x number of gallons per minute. Rainbird has a chart that will say, for example, a 15 foot nozzle that throws a 360 degree pattern (15F) at 60 PSI will use 4 gallons per minute (GPM).  Lets say all 15 heads have a 15F nozzle on them, then in one minute the system would use 60 GPM (15 heads times 4 gallons per minute =60 gallons per minute). You could use a pressure reducing valve to cut down the volume, but depending on what the pressure is currently and lets say the minimum pressure to work the heads properly (about 35PSI) the volume you save is probably not going to be significant. What I would suggest, is to change the nozzles on the heads to a lower volume nozzle. Toro now makes a nozzle that fits the Rainbird head that is low volume. For instance, as before the Rainbird 15F nozzle uses 4GPM, a Toro low volume nozzle at 15F might only use 2GPM (I'm just guessing ). The nozzle just simply unscrews from the top of the head without having to change the whole head. I hope this helps, good luck and have a great day.