Near Intersection of I-35 & I-90 Southern Mn. | Yes you need standard ON/OFF valves for the Boom sections. The Fast Close valve got its name because it is a single valve that was created to save a buck. It was designed to replace the standard control valve and standard ON/OFF valve that has been successfully used for years.
I have never been fond of them. The Standard Control valve which I recommend uses a motor and transmission to slowly turn the ball valve for rate control. This is its only function in life. It is not designed for shutting off the system. A standard ON/OFF valve is plumbed inline after it for the ON/OFF function.
The ON/OFF valve is either fully open or fully closed. The control valve is partially open to the point necessary to deliver the correct rate. When the Master switch is shut OFF, the ON/OFF valve cycles quickly stopping the product flow but the control valve stays at its current position.
With a multi-boom bar, the only difference is that more shutoffs are installed after the Master shutoff and liquid line connection. The reason that a Master ON/OFF valve is needed is to stop the flow to the liquid bleed line going back to the cooler.
Then the Boom switches can control these ON/OFF valves much like a sprayer. The Master needs to be tied into the Boom trigger lines with the "OR" gate that I mention so that it will be ON if one or more Boom Valves are ON and OFF when all the boom valves are OFF.
With a system using a Fast close valve for shutoff and control, the console must give very short shots of electricity to try to change the rate since there is no geardown transmission in the valve. When the system is shut off at the ends and then later turned back ON, the system must hunt for the correct valve position. It basically opens the valve until the rate is too high then backs it back down.
Contrast this with the standard control valve that is geared down and stays put when the system is shutdown since the ON/OFF valve stops product flow. When you turn the system back ON, the control valve is already in the correct positon if the ground speed is the same as when the system was shut off. This results in much better control especially at low rates.
For larger bars, we generally would use two completely separate accuflow systems. Generally each one controls its own half of the bar. So for a 60' bar each system is handling its own 30' section. This would require two 440's or a Raven console with two product capability such as a 4400, Viper etc.
It could probably be done with an Insight and Two Liquid Control Modules where each was set to do half of the bar. I believe there would be some problems with autoswath and mapping.
You may want to talk to Raven Tech Support on this if you further questions.
Edited by tedbear 4/15/2008 08:16
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