Please help with 3pt sprayer pressure issue

Beanboy · Mar 6, 2015

I bought a Fimco 3pt 60 gallon folding boom sprayer to apply glyphosate to foodplots. I also purchased a Devlon 6 roller pump. I am unable to get the pressure down below 75-90 PSI, even loosening the regulator valve almost to the point of total removal. Contemplating replacing the pressure regulator but am wondering if maybe I'm just using too much pump? Also considering adding boom extensions with additional nozzels on each end in hopes this would also help lower pressure so the sprayer tips will operate and apply the herbicide as designed. (35-40PSI)
As you can see I am a complete novice at this. Does anyone have any ideas to help solve the problem? Adding the extensions and extra spray tips are desirable anyway, but figured I'd seek guidance and get things fixed all at once.
Any experienced based solutions and opinions will be greatly appreciated

davesl708 · Mar 6, 2015

My sprayer is not nearly as large as yours. Only 25gal. My pump has a bypass hose that returns to the tank. By adjusting the amount of bypass I regulate the pressure to the nozzles. Does your unit have a bypass?

Beanboy · Mar 6, 2015

davesl708 said:
My sprayer is not nearly as large as yours. Only 25gal. My pump has a bypass hose that returns to the tank. By adjusting the amount of bypass I regulate the pressure to the nozzles. Does your unit have a bypass?

Yes, there is a hose that has continuos flow back into tank to keep things agitated/mixed but to tell you the truth I don't remember if it has a separate valve to adjust the flow. If my memory serves it is just a T fitting running a hose back into the tank. The sprayer is 5 hrs away at camp but next time I get there I'll sure take a look to find out. Even if it doesn't maybe I can rig an adjustable valve to help regulate things. Thanks for the info.

teg · Mar 6, 2015

Is this the unit? ...and pg 4 is where you unscrew to point of "Total Removal".

http://www.fimcoindustries.com/images/manuals/LG-60-3PT(FM699).pdf

Do you have the specs on the Devlon 6 roller pump??? Gallons per Minute, mainly...

Beanboy · Mar 6, 2015

Yes Sir that's it. My son went to pick up a 5 roller pump but they only had the 6. It's rated for max flow of 19.6 gals at 1000 rpm. I have totally unscrewed the knob on the relief value and manually moved the spring loaded plunger to make sure it is not stuck but was afraid to run the pump with knob removed for fear of blow-out and losing parts. Earlier today I emailed Pimco for assistance and they asked for pics of how the rig is plumbed and hinted if assembled incorrectly that might be causing the issue. I will send them pics next time I return to camp

teg · Mar 6, 2015

Might as well post the photos here too... might help someone else.

I find it odd that Fimco did not list or recommends a certain pto pump (or GPM)... I would have thought that it would come with one...

Beanboy · Mar 6, 2015

Guess they figure anyone buying that type of unit knows what they are doing. They didn't figure on us wannabes striking out alone. Some of the smaller units are offered with pump kits but was not an option at this store. The wife says I watched too many episodes of "Green Acres" as a kid and she may be right. At least I haven't run into Mr Haney yet!

hosspuller · Mar 6, 2015

Your pressure at the spray heads will be a function of the roller pump capacity and PTO speed plus volume bleed off. IE ... the pressure will be different with the nozzles on or off. I suggest you load the sprayer with plain water to adjust the pressure.

I spray at about idle speed, Change ground speed with gear selection. A lower pressure gives larger droplets that don't drift as much.

calman93611 · Mar 6, 2015

Ok, I took a look at my sprayer, just a hair smaller than yours, you set the pressure, from 0-115 psi, and whatever is not used is bypassed back to the tank. Might be the problem in the valve. I would try taking the valve apart, should be a 4 port valve 1) pressure regulator 2) inlet, 3) bypass 4) pressure gauge.
BTW, if you are using glyphosphate make sure that you are using either a plastic or stainless steel tank. Glyphosphate is acidic and will produce hydrogen gas in a galvanized spray tank. Also, glyphosphate is very sensitive to chemicals/minerals in water and should be used within 45 minutes. Add a spreader or wetting agent to the tank mix for a more effective application. A spray boom works great. I plumber mine for a spray boom and also a want on a long hose, have a valve to switch between the two. Good luck.