Dohrmann Applicator Setup Question

I finally had the need to use my Dohrmann Applicator with Hayguard on my round baler. Applicator has the variable speed control. By using the speed control knob on the controller I could vary the flow from basically 1 GPH @ 15 PSI up to the top end of the flow meter which is around 10-12 GPH. For my baling rate I set the speed control at 4 GPH which equaled about 20 PSI. Nozzle put out a nice fine mist.

Question 1 - What pressure are most guys running with their applicator. 20 PSI seams low, but the nozzle sprayed fine so that should be ok right?

Question 2 - Why would I need different nozzles if I can reach the entire range on the flow control meter using the speed controller.

Question 2 - When do you adjust the pressure relieve valve on the applicator vs using the speed controller on the applicator?

 

The system worked well. No clogged nozzle, and consistent flow, but I don't think I laid enough product on...I will have to check the bales today to see...

Dohrmann Applicator Setup Question