Backflow Prevention Practice Exam

The correct action to avoid freeze damage in pressure vacuum breaker shut-off valves and test cocks during winterization is to rotate ball valve handles to a 45-degree angle. This position helps ensure that any remaining water within the valve body can properly drain out, which is crucial in preventing freeze damage when temperatures drop. When valves are left fully open, there is a risk that water may still remain at the lowest points, leading to freezing and potential damage. Additionally, a 45-degree angle is typically effective in allowing for gravity drainage while maintaining a degree of valve closure that can remain operational in warmer conditions.

The purpose of the other choices does not effectively address the specific needs of winterization. Leaving all valves fully open may result in stagnant water that can freeze. Purging the body with compressed air can be beneficial but may not ensure complete drainage as effectively as adjusting the valve angle. Removing internal components is not practical for regular winterization and could lead to reassembly challenges upon restart. Thus, rotating the ball valve handles to a 45-degree angle stands out as the most effective method for protecting the system from freeze damage during winter.