Near Intersection of I-35 & I-90 Southern Mn. | I am assuming the Control valve on your sprayer is plumbed into the spray line. Some sprayers use a control to the hydraulic pump for rate control but I think this is unlikely for your sprayer. I'm also assuming that the control valve is a Raven brand which is plumbed in the flow leading to the flow meter and directly controls the flow to the ground. This is called "inline" or "throttling". The system controls this valve by calculating the amount of land being covered and the amount of spray being applied to calculate the Rate/acre. In Rate 1/2, the system will adjust the control valve in an attempt to get the calculated applied rate to agree with the target rate set by the operator. In MANual, the operator has direct control of the control valve and it will only move when the operator moves the INC/DEC switch.
The current Raven 440/450 has a control valve type setting in the initial setup. The correct setting for either of the above is Control Standard or C-SD.
When using this type of control, the control valve is NOT supposed to close when all the sections are OFF. The behavior that you describe is proper and I don't think there is anything wrong. When you shut off a section switch that section valve should close. The system is aware of this and the amount of area being covered is reduced in its calculations. The applied rate will then likely be somewhat high and the system will attempt to reduce the flow so that the applied rate will then be in close agreement with the target rate.
If you should shut off the Master or all sections switches, the system is aware of this BUT does not change the position of the control valve. Flow is prevented from reaching the ground due to all section valves going closed. This means that the control valve will be in a reasonably correct position when application resumes. If the ground speed, rate and number of sections coming back on are the same as when shut off, the control valve should not need to change.
If the control valve would shut down completely, there would be a reduced flow when spraying resumes as it would take a bit for the control valve to move to the proper position.
A question that sometimes comes up is "With all the valves closed where does the flow go?" The answer is nowhere except for the amount going to agitation which is tee'd off prior to the control valve, flow meter and section valves. This is not a problem for a modern centrifugal pump as long as there is some flow which is present due to the tank agitation line.
There are other type of control valve situations that the 440/450 can handle. There is the so called Fast Close Valve which is commonly associated with some NH3 systems. With those vales, a single valve handles the ON/OFF and control functions. The 44/450 is setup in the Fast Close mode and the valve WOULD close when all the sections are off. This is not relevant to your spraying situation.
It sounds as if you were expecting what is known as "Zero Speed OFF". This would mean you could throw the tractor into neutral, hit the brakes and come to a halt and the sprayer would shut itself off. Certain granular applicators work that way but not a sprayer such as you have. If you are going to stop, you will need to shut the Master OFF.
The valve cal number of 2123 that you mention affects factors such as how quickly the control valve reacts, how close is close enough etc. The value of 2123 is a recommended starting value and is often fine. You can experiment with the digits to get the system to react more to your liking. This does not cause the valve to close when the booms are OFF or the speed goes to zero.
Edited by tedbear 5/29/2020 07:28
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Raven 450 on Sprayer help
