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

I had a couple of questions about the Hunter PGP rotors. The ADJ version seem cheaper than the 360. I would think the ADJ would be more expensive because of the extra mechanism that makes the adjustable? Or do most people simply buy the ADJ and leave them at the 360 setting, so Hunter makes lots more ADJ's than 360's?

The site http://www.irrigationtutorials.com/sprinkler15.htm recommends avoiding nozzles sizes of less than 3.2 gpm @ 30 psi for full circles. According to the Hunter PGP red nozzle chart, that means at least a #8 at 30 psi and a #7 at pressures above 45 psi.

I have also seen nozzle recommendations on these forums for smaller nozzles. Is the 3.2 gpm per nozzle a hard rule or are there other considerations?

Thanks,

Sorry, tried to edit the post above.

The minimum recommended is 2.5 gpm, not 3.2 gpm.

The 3.2 was the minimum for 29 ft max spacing.

Thanks,

If I am using 1 inch poly for laterals, 1 inch poly has a maximum recommended flow rate of 13 gpm or less. That would mean a maximum of 5 rotors at 2.5 gpm or 4 rotors at 3 gpm. More rotors would require going to either 1.25 poly or 1 inch Class 200 PVC.

So if I want to use 1 inch poly, I need to check what pressure I have at 13 gpm or find gallons per minute at 50 psi. Both of these should be fairly simple to determine with a Tee, a pressure gauge, a ball valve and a bucket.

Thanks,