This model tests the ValveLiq model zero or reverse flow conditions.
Simulate the model for 4 s. At t = 1 s the V5 valve closes in 1 s, the V2 and V3 valves close in 2 s and the V1 and V4 valves open in 2 s. The flow in valve V3 reverses between t = 1.83 and t = 1.93.