Backflow Prevention Practice Exam

During a backflow test, if a check valve fails, what is the likely outcome?

1. Purge the system

2. Water will flow backwards

3. Pressure will increase

4. Normal operation will continue

The correct answer is: Water will flow backwards

When a check valve fails during a backflow test, the likely outcome is that water will flow backwards. The primary function of a check valve is to prevent water from flowing in the reverse direction, ensuring that it only moves in the intended direction of flow. If this valve does not seal properly due to a malfunction or failure, it can no longer perform its crucial role. This means that pressurized water from the downstream side can travel back into the upstream system, potentially leading to contamination of potable water supplies and creating unsafe conditions in the system. In this context, options such as purging the system or experiencing increased pressure are not direct outcomes of a check valve failure. While a failed check valve may eventually necessitate system purging to eliminate contamination, this action would be a subsequent measure rather than an immediate outcome of the failure. Normal operation continuing is not plausible because the failure of the check valve disrupts the intended flow and allows backflow, leading to potential hazards. Therefore, the inability of the check valve to prevent reverse flow is a critical issue that must be addressed urgently.