Sprayer What PSI for a sprayer?

[chucko]

Just built me one. What kind of PSI do you guys run yours at?

 

[nomad]

What sprayer do you have? Field sprayer with 25-30 ft boom? And the nozzles are elliptic? THEN,

From 100 gallons to 1000 gallons, same pump can be used and their delivery pressure will be about 600 psi.
For 1000 and more gallons, this pressure will go upto 750 psi.
Note that if you use longer booms, your pump pressure will be higher as there will be more pressure loss (due to the boom length and due to extra nozzles.)

 

[chucko]

I built a small version of what you showed to spray the yard ( 55 gl tank) kind of like the 3 point ones tractor supply sales but don't want to put too many psi to it and start poping hoses off. Got any idea how many psi the pull behinds at tractor supply run?
I had the thing running last night and could get 50+- with the tractor at idle speed. So I am sure that the pto pump would realy get going if I ran it at 540 rpm
Maybe I could have this thing duble as a fire truck if I unhooked the boom /forums/images/graemlins/tongue.gif

 

[Bird]

Chuck, as for the pressure, it varies greatly. What kind of pump are you using. The 12 volt ShurFlo pumps on some of the rigs like TSC sells only run up to a maximum of about 60 psi. The HyPro roller pumps for electric motors I believe run up to 90 psi while the ones for the tractor PTO run up to about 300 psi, then of course there are other brands and types made that will run higher, as Nomad mentioned.

 

[zuiko]

Of course you could just keep at at idle too if you put it in a high enough gear. That is what I plan to do. I will never even approach 540 with my PTO pump, I think 50 is enough.

 

[higgy]

It depends on the nozzle and what you are spraying. I have 30' booms, nozzles are eliptical and the spacing is 32 inches. I spary from 20 inches from the ground and have a slight overlap at 20-30 psi. With this pressure and a 5% solution of 2,4-D or roundup that gives me a feild speed of 4 mph to give the correct appication rate to the field.

I have never known anyone to use pressures in the hi 10's or in the 100's of pounds.

Having said that there are a lot of things that I do not know going on in fields every day.

The idea is to coat the plant with a nice even coat and maybe use a preader/sticker, not to blow the leaves off with high pressure spray.

Just my 0.02

Dane

 

[OrangeGuy]

I just hooked up my 60 gal 3 pt sprayer with 20' boom. I am using a Hypro 4001 roller pump and standard fan tip spray nozzles. My spray nozzles put out 20 gal per acre at 35 psi. They are set 20" apart and I operate at about 24" off the ground. I spray at 5 mph.

I'm off to spray about 50 acres at the local Catholic High School. I volunteer to spray every year for the tax deduction.

OrangeGuy

 

[OkieG]

Chuck,
Don't know much about a BX 1800, but by the size of the implements you have listed, I'm guessing the "1800" is for ~18hp...about the size of my tractor.

I have a TSC Fimco 55 gal sprayer with 7 "8002" sized spray tips on a ten foot boom. Perhaps, that is close to the size sprayer you have built? I mentioned the tip size only because it may mean something to you...tip size means nothing to me!?

The scale on the pressure gauge goes up to a whopping 400psi. However, the Fimco manual says, "When selecting pressure from the tip chart, it is a good idea to try for the 20-30psi range as this allows an excellent nozzle pattern. 10psi begins to break up the pattern and at 40psi, you may notice some drift." I suspect optimal pressure varies from one nozzle type to another.

I liken "drift" to "overspray" in paint jargon, which in my mind includes not only the paint that outright misses the target, but also the mist of tiny droplets that form in the air around where you spray. The same thing happens with the spray nozzles on a tractor sprayer. At some angles, in the right light, it's amazing how much "drift" you can see occuring.

Lower nozzle pressure = less drift and more of the spray product on the desired target. The herbicides most of us spray are not Agent Orange, but I still don't want to be breathing any more than necessary, or getting drift on non-target plants, the kids, etc., etc..

A pressure just above where break up occurs is your best pressure. I run my sprayer at 20psi. You may have to experiment a bit to find the right pressure for you.

OkieG

 

[OkieG]

<font color="blue"> Of course you could just keep at at idle too if you put it in a high enough gear. That is what I plan to do. I will never even approach 540 with my PTO pump, I think 50 is enough </font>

I think you're right. Idle engine speed may well generate enough pump flow/ pressure for your desired nozzle pressure. At least, probably not much above idle will. On my little sprayer, excess flow goes to bypass and returns to the tank. The valve maintains a constant pressure to the nozzles pretty much regardless of engine speed. Just pick a comfortable engine speed and go.

OkieG

 

[dixiedrifter]

My sprayer is set up using TeeJet XR 80 nozzles I think, 8 roller hypro pump, nozzles spaced 20", pressure at 30 PSI, and boom 30 inches from the ground.

Run my tractor at 1500 RPM (2200 RPM=540 PTO) in 4th gear puts out about 19 gpa with no problems with pressure.