Sprayer Rotary vs DC pump for sprayer

[dcsobob]

Hello all,

Roger newbie here.

So, the age old question. What size/type pump do I need for a sprayer. I have a 26hp Mahindra with Cat 1 hitch/PTO. I have a horse farm with my pastures divided up into 1-1.5 acre sections for rotation.

I need to spray them for weed kill and fertilization. Prior to getting the new tractor I was using a 25gal tow sprayer pulled behind my lawn mower. Worked okay with the annoying downside of needing to go keep filling it up to get the spraying done.

So, now with the tractor I want to get a bigger tank setup.

I have seen several models of 55-60 Gal tanks that utilize a 2.2GPM 12VDC pump that sell for about $400. Same size tank, or maybe bigger that is using a roller pump. I did some research on what a roller pump was. Got the basic understanding.

When talking to my local Coop person about getting a 12vDC sprayer he said it would be a bad idea for my tractor as I would not get the pressure I needed. Not real sure where he was getting that from.

So, looking for education. Is there any reason why a 60Gal sprayer sporting a decent 12vdc pump would not work in my case? Should I be looking at a roller pump and if so why?

Thanks.

 

[Squeak n Itch]

Think of it this way. If you took your old pump and sprayer nozzle system and moved it from the 25 gallon tank to a 100 gallon tank the only thing that would change is the small amount of power to carry a 4x larger tank. 4x fewer refills will be necessary. Win/win!! Starting from this simple premise you could increase as much as you want and perhaps cover more area but at 1.5 acres at a time this seems somewhat pointless.

 

[Rocky Hoffler]

I had a 25 gal 12volt sprayer worked ok until I stepped up to a 55 gal pto 3 point hitch sprayer with a tip that would cover 18 or so feet and a wand that we added hose to give 50 feet reach pressure is adjustable up to 100psi with the wand you could get 35 to 40 feet straight up. I would recommend you not use sprayer with heracide to also put out fertilizer this is acourse IMHO

 

[Dingeryote]

With the little tanks, the 12v pump doesn't have to move much volume on bypass to keep things agitated sufficiently.

It's a completely different matter with a 60gal tank. The 12V pumps simply lack the volume to meet the demand, unless you get silly with the pump cost.
If you are going to be running water soluble fertilizer, and other solubles to save $$$, energetic agitiation is a must.

Another factor is the 12v diaphragm pumps are essentially worthless when it comes to holding up with flowables in the tank.
They do NOT like sucking up a glob of half dissolved pre-emerge, AMS, or water sol fert.
Drop big dollars on a 12v pump that will meet your volume needs, and then choke a diaphragm and it's time and money down the crapper.

Hypro and Delavan 6 roller cheapies last 2-3 seasons on a rebuild if they are cleaned out after use, and stored dry and oiled in the off season.
Best part is, they run under 100 bucks of you shop smart, and will meet every demand you may have easily.

 

[Cord]

That pump is too small. Sounds like maybe you could start watching cragislist for a old tow behind ag sprayer.

 

[clayhardock]

Since you are successfully using a 12v pump now I don't see why it won't work for you if all you are changing is the tank size.
Now it you are planning to add a bigger boom or more nozzles then yes you would need more pump.

 

[TomSeller]

My 2.2 GPM pump came set up for 70 psi. I reduced it to 35 psi, so there should be no issues in getting pressure out of a 12V system. GPM might be an issue with that much tank capacity depending on your method of delivery.

 

[jenkinsph]

Keeping the tank mixed well is an important consideration. This can work at a low pressure flow or high pressure flow as long as you have enough flow rate.

How much pressure you need depends on the method of spraying used. For applications requiring that you atomize a mist you need higher pressure to do that, up to 300 psi in most cases. If you use a wand and need a stream to coat the vegetation a low pressure system of 40 psi will work well. I would think about the long term needs and if you need to mist with a boom go with a good roller pump if you only need to spray the simple stream a low pressure pump will work. Recognize you can turn the roller pump pressure bypass down but you can't turn the low pressure pump up beyond its design limit.

 

[RPW]

For my sprayer rig I built it using a 125gal. tank and a 7gpm electric pump. With 9 nozzles I can cover a 14ft. path. The nozzles are .4gpm and the system runs at 40psi. So far I haven't had any problems with water soluble fertilizer and GrazonNextHL broadleaf weed killer. This next year I will be adding 4 more nozzles and will be upping the nozzles to .5gpm. That will give me a 18 to 20 foot path and I'll still have enough extra gpm for agitation of the mix. I did it this way as it was about half the cost of a PTO driven rig.