Sprayer rate controller and ramsey valve pressure control

[john63]

My (new to me) Gem sprayer has a ramsey type pressure controller and an RDS Delta 34 rate controller.

I've only ever used a sprayer with valve/bleed off type of pressure control before and no rate controller! I understand that I pressurise the ramsey valve to the pressure I want to spray at. The rate controller will then vary the spray pressure via its valve to keep the output the same as the speed increases or decreases.

So, if I nominally want to spray at say 3 bar, and for the sake of argument, the rate controller can vary the pressure between 2.8 and 3.2 bar, what pressure should I pump the ramsey valve up to? Presumably the rate controller can only reduce the pressure below the ramsey setting, not increase it?

Thanks.

 

[tullah]

My (new to me) Gem sprayer has a ramsey type pressure controller and an RDS Delta 34 rate controller.

I've only ever used a sprayer with valve/bleed off type of pressure control before and no rate controller! I understand that I pressurise the ramsey valve to the pressure I want to spray at. The rate controller will then vary the spray pressure via its valve to keep the output the same as the speed increases or decreases.

So, if I nominally want to spray at say 3 bar, and for the sake of argument, the rate controller can vary the pressure between 2.8 and 3.2 bar, what pressure should I pump the ramsey valve up to? Presumably the rate controller can only reduce the pressure below the ramsey setting, not increase it?

Thanks.

I usually put 4 bar in so if I want to drive a bit harder there’s plenty of leeway left to increase the output.

 

[Flat 10]

My (new to me) Gem sprayer has a ramsey type pressure controller and an RDS Delta 34 rate controller.

I've only ever used a sprayer with valve/bleed off type of pressure control before and no rate controller! I understand that I pressurise the ramsey valve to the pressure I want to spray at. The rate controller will then vary the spray pressure via its valve to keep the output the same as the speed increases or decreases.

So, if I nominally want to spray at say 3 bar, and for the sake of argument, the rate controller can vary the pressure between 2.8 and 3.2 bar, what pressure should I pump the ramsey valve up to? Presumably the rate controller can only reduce the pressure below the ramsey setting, not increase it?

Thanks.

Does it not have a compressor and air reservoir so it can raise it and decrease it? Not familiar with that controller but don’t you just set rate and it sorts out the rest?

 

[fudge]

My (new to me) Gem sprayer has a ramsey type pressure controller and an RDS Delta 34 rate controller.

I've only ever used a sprayer with valve/bleed off type of pressure control before and no rate controller! I understand that I pressurise the ramsey valve to the pressure I want to spray at. The rate controller will then vary the spray pressure via its valve to keep the output the same as the speed increases or decreases.

So, if I nominally want to spray at say 3 bar, and for the sake of argument, the rate controller can vary the pressure between 2.8 and 3.2 bar, what pressure should I pump the ramsey valve up to? Presumably the rate controller can only reduce the pressure below the ramsey setting, not increase it?

Thanks.

You are correct, the rate controller can only produce operating pressures below the Ramsey pressure.The pressure in the Ramsey should be set above the maximum expected spray pressure. So in your example I would set the pressure at approx 4 bar.

 

[S.Jamieson]

Yep, I set mine about 4.

What sprayer have you bought?

 

[john63]

Thanks for the replies.

I usually put 4 bar in so if I want to drive a bit harder there’s plenty of leeway left to increase the output.

Thanks, sounds like 4 bar is the way to go.

Does it not have a compressor and air reservoir so it can raise it and decrease it? Not familiar with that controller but don’t you just set rate and it sorts out the rest?

No, it's got a tyre valve for the Ramsey. It's a case of pumping it up manually with a foot pump or similar before going spraying.

You are correct, the rate controller can only produce operating pressures below the Ramsey pressure.The pressure in the Ramsey should be set above the maximum expected spray pressure. So in your example I would set the pressure at approx 4 bar.

OK, thanks. It's as I thought then, will likely go with 4 bar or so.

 

[john63]

Yep, I set mine about 4.

What sprayer have you bought?

I bought it in June last year, but have been sorting out a few issues with it since. It's done a lot of work so there's a fair bit of wear in the pivots, but it was very cheap and a major step up from a 12m 800l mounted.

 

[fudge]

The good thing about your set up is that if you have an electric glitch it's still possible to spray accurately in a manual mode with a constant pressure and speed etc. The best thing about the rate controller is that it will balance the operating pressure when individual sections are switched off. Obviously in manual mode it's not easy to do that.

 

[Andy26]

The good thing about your set up is that if you have an electric glitch it's still possible to spray accurately in a manual mode with a constant pressure and speed etc. The best thing about the rate controller is that it will balance the operating pressure when individual sections are switched off. Obviously in manual mode it's not easy to do that.

With a Ramsey valve in manual mode it will be far superior to a rate controller at maintaining pressure constant on all sections.

 

[fudge]

With a Ramsey valve in manual mode it will be far superior to a rate controller at maintaining pressure constant on all sections.

No not in my opinion. It should be the same. The rate controller is very good in a straight line at a constant speed. It's only if you have a fault, for example in the wiring, manual mode allows you to complete the job without taking the time to trace the fault that's all. Sophistication on sprayers is very good as long as it is working, breakdowns are very frustrating not lease because you are stuck with a tankful of chemical. I think you will soon get use to your system!!!

 

[tullah]

No not in my opinion. It should be the same. The rate controller is very good in a straight line at a constant speed. It's only if you have a fault, for example in the wiring, manual mode allows you to complete the job without taking the time to trace the fault that's all. Sophistication on sprayers is very good as long as it is working, breakdowns are very frustrating not lease because you are stuck with a tankful of chemical. I think you will soon get use to your system!!!

I’ve been caught with a tank full before and then rained off for a week.
Every sprayer needs to come with a simple changeover valve to bypass electrics ready to go to fully manual. There can easily be £3k worth of chemical in a big tank wasted.

 

[john63]

The good thing about your set up is that if you have an electric glitch it's still possible to spray accurately in a manual mode with a constant pressure and speed etc. The best thing about the rate controller is that it will balance the operating pressure when individual sections are switched off. Obviously in manual mode it's not easy to do that.

Absolutely. Not too much sophistication on the sprayer controls side, just a few switches and no electronics apart from the rate controller. Had a few issues with the hydraulic solenoids, but a few replacement connectors and a bit of wiring sorted it out. I didn't actually realise that it had a rate controller until I went to collect the box from the office at the sale I bought it from.