From the Autodesk App Store...
This is a TRIAL app. After installation, when Autodesk® Revit® is started, the user will be asked to activate the trial. To activate the trial, the user must obtain an activation code, which can be generated on our website (clicking the Activate button directly in the WCS app will take the user to the activation web form). The user must submit first name, last name, and email to which the activation code will be sent.
Trial means fully functional application for 30 days after the activation.
GENERAL DESCRIPTION
In general, "Water System Calculations" is providing three key features:
1. Conducts flow calculations according to DIN 1988-W308 norm, frequently used in Europe.
The application adds user defined flow calculations for Domestic Water System into Revit Mechanical Settings (under Pipe Settings / Calculation / Flow / Calculation Method), which uses Fixture Units (defined in plumbing fixtures families) to calculate water flow.
2. Calculates pressure loss on critical path and shows critical path for Domestic Water System or Hydrant System
One major and unique feature is critical path finder. It will find the critical path with the highest pressure drop combined of friction and elevation losses along the path. The final result is total pressure drop. Revit finds the critical path as well, but it does not take elevation into account.