Revit MEP provides a tool to know flow rate and pressure for each section of the system such as Ductwork and Pipework, this tool is called System Inspector.
Here is an example for inspection an air system, select the whole system, the ribbon will be changed as shown, click on System Inspector Icon.
Now you can check any section just hover your mouse over it, you will get the data as shown
After finishing the check-up process, click Finish button.
