Roller pumps

ROYCEWILLARDOKLAHOMA · Mar 24, 2013

I need to talk to one of you Men about choosing a roller pump. The one I bought may be too big for the job. What Im wanting to do is spray pastures , I bought the 6900 series delavan 8 roller 23 gallon a minute , and bought 2 nozzels and a 260 gallon tank . The nozzels are 1/2 inch and with #10 orfice . is this too much pump? I havent even put it together yet so I can take it back if I need to. I have less than 200 dollars tied up in it so far so I know I havent messed up too bad. I just know that the pump can put out 300 psi and started thinking that when I start the pto turning that I better have enough nozzels for all that pressure or its gonna go some place, and I probably aint gonna like it. lol What do you Guys think? Ive looked at a lot of the sprayers on here and most of them look more sophisticated than what I wanted. I would like to have the bare minimum gadgets on mine that I can have . Ive done a lot of spraying with the spreader bar and 12 volt pumps. This will be my first roller pump setup . Im wanting to spray at least a 20 foot swath with each pass. I have a lot of spraying to do and dont want to turn it in to a career. I have been using Gly on fences and remedy on the pastures after the first cutting with great success , But it just takes to dang long with the 12 volt pump and boom. plus here wher I live we have lots of trees and tight places where a boom is just obsolete. Do you folks think this is too much pump. Am I gonna be blowing lines up?

oldbones · Mar 24, 2013

Thing to do is find out gpm your nozzles put out. "1/2 inch and with #10 orfice" doesn't tell us anything. Need to know what your sprayer tips put out (gpm at "X" pressure) and the chemical you're spraying has recommended water droplet sizes (for drift control and for proper dispersion/soverage pattern). Pressure directly affects water droplet size.
As far as 300 psi pressure, heck yes that's too much for ANY crop sprayer. I use Teejet 80 degree fan XR nozzles @25psi, and TeeJet 110 degree fan Air Inducted nozzles @ 50 psi on my field sprayer. You also need to recirculate to the tank to keep it mixed. In my opinion, a centrifugal pump would be a better pump, but it sounds like you've got too much pump. But, there again, need to know gpm/gpa requirements, not pressure, to get started.

hosspuller · Mar 24, 2013

Any roller pump is a positive displacement pump. You need a pressure regulator with relief. If you don't have a relief... Boom! A relief port is useful to keep the tank agitated with the excess flow.

As for your specific pump, Likely The 23 GPM is rated at 540 rpm. BUT ... a large displacement pump will allow you to idle along at less than 540 RPM at the PTO spraying at full capacity. I've found rough ground, long boom arms and fast speed makes for bouncing spray booms... and missed weeds.