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Active Member


Saturday, September 10th 2005, 3:02pm

adjusting valve flow control

Are there any tips for adjusting the flow control on Rainbird PGA valves?

Specifically what should I be looking for in spray patterns?

I had adjusted one or two zones down a bit because of misting. There seemed to be too much pressure at the Rainbird 1804 SAM-PRS sprinkler heads.


Supreme Member


Sunday, September 11th 2005, 1:59pm

install a pressure gauge on the last head on whatever zone your testing. adjust the flow control till the gauge reads 30psi.


Active Member


Monday, September 12th 2005, 2:42am


Is there a special adaptor available for the nozzle fitting? If not, then I'll make up an adaptor for the pipe thread fitting the head screws onto.


Supreme Member

Posts: 5,298

Location: Metro NYC


Monday, September 12th 2005, 4:02am

Rainbird 1800-PRS heads already have internal 30 psi regulators. You must have really high pressure (or defective regulators in the heads) for the adjustment to make a difference. Usually, anything under 75 psi is normal for those heads.


Active Member


Tuesday, September 13th 2005, 2:48am

The water pressure is high coming into the house. It is in the range of 80-85PSI and I don't complain about the high water pressure. I am sure that the double check valve and piping have cut this back a bit. Maybe the pressure at the heads is close to their max? I haven't checked this yet and will try to attach a gauge to the last head connection on the zone to see what the pressure really is.

I did turn the valve's flow control down to 50% (about 4 turns fully open then back 2 turns) and this made a difference.

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