What causes the RV to spit?

When considering what causes a reduced pressure backflow preventer (RV) to spit, line pressure fluctuation is a significant factor. Spitting occurs when there is an inconsistency in the line pressure that affects the proper functioning of the backflow preventer.

When there's a fluctuation in line pressure, it can lead to the backflow preventer either opening or closing unexpectedly, allowing water to escape through the venting mechanism. This is often a temporary reaction to changes in pressure that are either too high or too low, which can happen during peak demand or sudden changes in the system.

Understanding this mechanism is crucial for maintaining the functionality and effectiveness of a backflow prevention system. Proper installation can mitigate some issues, and leaks in shut-off valves generally cause different symptoms that are not directly connected to the spitting behavior observed in the RV.