Sprayer issue

[Dadnatron]

Purchased a new (to me) used sprayer and have been going over it.

I had everything seemingly working well, and sprayed alfalfa yesterday without problem until about 3/4 through the last tank. I noticed a pressure drop (not exactly sure when it happened, but couldn't have been more than a second or two without looking at the nozzles) and saw a change in the nozzle spray. Pressure had been running right at 60psi and all of the sudden was around 10-15. I thought a hose busted, as that is how it was acting... as if there was a pressure release somewhere and the spray was just what was left over. I stopped, checked over all nozzles and hoses, and everything looked good. But as soon as I started ANY of the booms to spraying, the pressure dropped from 60-70 to 10. My pump was capable of pumping a 70 psi (as monitored on the in cab gauge) And previously, the in cab and separate boom gauges were within a psi or 2.

Turning on any boom segment caused an immediate drop in pressure. I thought that the issue could be at the manifold with a big leak there... but I can't find one. I was able to wimp out the remaining 30-40 gal, but the spray was extremely course and the psi was about 10. I rinsed the tank with an additional 20-30 gal (240gal tank) and sprayed it on a safe area.

I'm stumped. If something was clogged or closed down, the pressure should be high or some boom segment shouldn't be working. But all were spraying... just really poorly. If there was a leak.... (which is how its acting) I should see something.

I can't think of anything in the manifold/valves which would cause this issue. I won't have time to take a look at it again until the weekend but man... if you have any ideas, I'd sure like to know.

This is the manifold and I can't remember the type of valves, but they are common basic valves.

 

[rustyshakelford]

Does it have a filter screen? Sounds like that was plugged or something was occluding it when it calls for flow. Why are you running at such high pressures? Most are figured at 40 psi for nozzle flows. Sometimes the higher pressures will cause the spray mist to be a little to fine and gets carried worse than a larger droplet

Brett

Just zoomed in on your second pic. Check the white filter and the inlet on the tank

 

[MortOz]

That sounds a lot like a blockage in the pump input line - check the filter, inlet in the tank, lines between the tank and pump. It seems as if it can build up pressure when there is no/limited flow, but when there is demand for normal flow rates there is not sufficient liquid into the pump for it to maintain its output. (And, 60psi sounds a little high - you aren't getting too much drift due to small droplet size?)

 

[Dadnatron]

I'll check it and hopefully it is the issue, although I can't think of how it could be clogged as I checked it the day before. Hopefully that is it, although, the filter is UPstream from the last valve, which is where the 'in cab' pressure is measured. If the issue is in the screen, how would that cause a drop? Does the blockage allow enough pressure to build when everything is shut but as soon as its released, it can't maintain? Perhaps that is it, and something just 'broke loose' and clogged the filter.

I visually checked all hoses, and they all appeared to be normal. I checked circulation in the tank and it seemed normal. I didn't pull any hoses though.

 

[rustyshakelford]

I'll check it and hopefully it is the issue, although I can't think of how it could be clogged as I checked it the day before. Hopefully that is it, although, the filter is UPstream from the last valve, which is where the 'in cab' pressure is measured. If the issue is in the screen, how would that cause a drop? Does the blockage allow enough pressure to build when everything is shut but as soon as its released, it can't maintain? Perhaps that is it, and something just 'broke loose' and clogged the filter.

I visually checked all hoses, and they all appeared to be normal. I checked circulation in the tank and it seemed normal. I didn't pull any hoses though.

Somewhere between the tank and the pump should be a filter screen or something inline to prevent contaminates into the pump. When it’s not spraying it’ll build pressure, when you call for flow, the pump doesn’t have the supply available to satisfy it. It could be something as simple as the plastic cover on a chemical bottle or a leaf that got in the tank. I think you have a very simple repair just needed to spend a bit running the lines. The issue will be between the tank and the pump id bet. If it was after the pump, the pressure wouldn’t drop but the flow would suffer

Brett

 

[Dadnatron]

I am running Teejet blue AI nozzle tips for 20gal/ac. At 5.5mph, which gets me 4th gear at around 540PTO, I get about 60psi, which is midrange for this nozzle tip. This gets me very coarse droplets to prevent drift. This gets me the 20gal/ac for Thunder on alfalfa/orchard. I've read that volume with Thunder (Pursuit) is key to insuring best results.

I think I will change to blue AIXR though, as my current nozzle tips seem too coarse... which was made much worse when pressures dropped. But the chart still says to run them at 60psi (mid range). Allowing me to drop rpm and not lose quality of spray. (According to Tom Wolf in the video below)

 

[DLTTrekkers]

I ones found an apple in the tank. Tank did not have a lid on !

 

[Dadnatron]

Thanks Brett, I'll check everything, but I don't think this sprayer has ANYTHING between the tank and the pump. It is a straight corrugated hose from the tank outlet running straight into the pump. (I think it is just that old). The sprayer is in pretty good shape, but it is pretty old technology I believe.

The pressure regulator is in between the filter and the valves... could this be the issue? When I was checking everything before, I could tweek the pressure up/down from the cab, but I think the switch is crappy as it feels 'soft/weak/sloppy' But it worked. When everything was out of whack, the pressure switch (Teejet 744A) didn't work either. I chalked it up to everything wrong with pressure. If the filter is clear and all hoses are clear... how would I check the pressure regulator?

 

[DLTTrekkers]

Thanks Brett, I'll check everything, but I don't think this sprayer has ANYTHING between the tank and the pump. It is a straight corrugated hose from the tank outlet running straight into the pump. (I think it is just that old). The sprayer is in pretty good shape, but it is pretty old technology I believe.

The pressure regulator is in between the filter and the valves... could this be the issue? When I was checking everything before, I could tweek the pressure up/down from the cab, but I think the switch is crappy as it feels 'soft/weak/sloppy' But it worked. When everything was out of whack, the pressure switch (Teejet 744A) didn't work either. I chalked it up to everything wrong with pressure. If the filter is clear and all hoses are clear... how would I check the pressure regulator?

I ones had a hose seperating the inner from the outer ....looks fine but could not suck water . By removing it queckly I saw it going back to normal !

 

[orangeandgreen]

I had a problem last year with an occasional pressure drop on my sprayer and traced it to the hose on the suction side of the pump collapsing. I replaced it with a "suction hose"
and no more problem. When I bought the sprayer new at the local farm store, all the hoses on it were the black "pressure" type.

 

[Dadnatron]

That is the same hose I am currently using. I haven't had time to check whether it delaminated as DLTTrekkers discussed. But something is happening. I agree though, the more I think about it, it sounds like a supply side issue.

 

[Dadnatron]

I am at a loss. And I guess I am going to have to begin taking the whole **** thing apart.

I've gone over everything visually and there is nothing clogged. I've pulled the screen and it had a bit of junk, but really nothing. The agitator seems very powerful and I can get a closed system 60psi. I can maintain it with my center section on (but for some reason it is truly only a single nozzle). But if I open either right or left boom, pressure drops from 60psi to 20 and if I open both, it drops to about 8psi.

I've removed the hoses from the valves, and they are flowing 'well'. But I already expected that as I can get water out of all nozzles, just at a very decreased pressure.

I don't really know where to go from here. My options, as I see it are:

1. Bad pump... able to get pressure against a closed system but cannot maintain it when open.
2. Delaminated tank to pump suction hose, allowing 'some' water but acting as a functional limiter.
3. Disfunctional pressure regulator.

The system is so 'simple' I can't think of anything else. It was functioning at pressure for at least 18 of the 20 ac I was spraying, but I am not exactly sure when it dropped. I just noticed that it had and been trouble since that time.

I guess the easiest is to remove and check the hose.
Then pull and replace the regulator.
Then finally pull the pump apart, which is really something I don't want to do if I am not sure it is the issue.

Any more thoughts?

 

[DLTTrekkers]

How much do you need to spray ? Can smaller nozzles do the trick ?

 

[rustyshakelford]

Man I’m racking my brain, how does the pattern look if you do each section individually? Have you confirmed you didn’t lose any spray tips and that’s where the pressure is going. Only other thing I’d say is bad pump. Weird

Brett

 

[Dadnatron]

I think I figured it out. I think it痴 the pressure control switch on the controller.

I was flustered and clicking several switches and all of the sudden, pressure increased. Now, I壇 been messing with that switch over and over, but this time it seemed to click in. I was able to get the pressure to stay up, but it seemed labile. Up a little and then down, but it was definitely different.

It became dark so I couldn稚 make sure. I took the controller apart, but the pressure switch is part of a circuit board and I couldn稚 remove it. I値l check it tomorrow, but I don稚 know if it doesn稚 work, I don稚 know if it can be repaired. I don稚 know enough about repairing something soldered to a board.

Hopefully my Findling will have done something good... it痴 hard to stomach purchasing a new one... especially since I致e seen the minimal insides.

Teejet 744