Permeate reverse flow

Hello everybody 

In RO desalination plants, sometimes it is inevitable to eliminate permeate line backpressure due to specific process design or product line static head. In these cases, there would be a destructive permeate backflow when unwanted high-pressure pump shutdown happens if there are no preventive facilities on permeate product line.

I was wondering what anybody has experienced as the best or most reliable scheme foreseen to overcome this issue.