Near Intersection of I-35 & I-90 Southern Mn. | I'm confused as to what your NH3 setup is.
If the bar is divided into two sections and you are using the standard control valve you would need three ON/OFF valves to handle the bar. In this setup the Control valve controls the rate and does not move at the field ends. The flow then goes to the Master ON/OFF valve which is usually a normal Raven ON/OFF valve for NH3, the output from this valve splits and goes to the Left ON/OFF and the Right ON/OFF valve. The Master valve is wired so that it will be open when one or both of the section valves are ON. If both valves are cycled off then the Master will go OFF also. The Master valve is necessary to stop the NH3 prior to the Left and Right valves to prevent liquid from continuing to feed the cooler and exit through the vapor lines.
The control valve setting is just that - it affects the speed and sensitivity of the control valve and has nothing to do with the ON/OFF valves.
If you are using a Fast Close valve for both control and the Master then the Fast close suggested settings for the control valve should be used. The check box should be checked indicating to the system that it should close down when the sections are off. You would still need to have standard ON/OFF valves for the sections. Once again the settings set for the control valve will have no affect on these valves.
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Slow valves with DirectCommand and NH3
