How to combine 2 system LU and FV for water pipe sizing

Revit
1

Hello,
I have two systems for the water Flushing valve and the Loading units. Somehow I cannot combine the two together because of the connectors. If I change the connector to FIXTURE units in revit I cannot control now the Flow because it will use the FU parameter.If I use PRESET TYPE then the FU will not available in the pipes which will be my source of automation in dynamo.
How can I combine the Flushing valve and the Loading Units together?

fv and lu
fv and lu1679×1040 125 KB

Loading value to flow
Loading value to flow1055×926 92.7 KB

2

I have already the Dynamo script that will autosize it. But I am having problem integration the 2 system

script
script1479×913 153 KB
Automatic pipe sizing revit selection 2018 WATER v1.dyn (24.3 KB)