Homer,No you would only have 1 line into the display. What was posted above is just a "U" if you will, made with 2 "T" fittings.
T off the return into the UV with a gate valve to adjust the flow into the UV while not disrupting the flow into the display, then T back into the return line. The "U" goes into the UV, while you still have a straight line past the UV like a normal return line.
Thanks for the info, if you look at my pics above i have a ball valve just above the return (for future stuff). Can I run the UV into that and maybe mount it on the wall next to and above the return pump and then somehow run it back into my return line before it gets to the DT???