A Warning message in AFT Impulse.

This Warning is followed by a list of all pipe stations with Vapor Volumes between 10 and 100% of the liquid volume, shown in the format: Pipe X, Stations: Y (Z%).

Vapor volumes between 10 and 100% of the liquid volume indicate that substantial transient cavitation is occurring at that point in the system. Impulse's cavitation models are meant to capture limited transient cavitation in a system, and have limited accuracy as vapor volume increases. In many systems, this amount of cavitation can be cause for concern, as it can lead to substantial waterhammer effects.

Users should explore the various cavitation topics - and in particular the Interpreting Cavitation Predictions topic - listed below in the Related Topics section to better understand what is causing these results, why they are possible, and how to interpret results in scenarios seeing this warning. If all else fails, users should treat systems with these results with caution, and incorporate large safety factors into their designs.