During an obstruction investigation of a sprinkler system, how many cups of scale can be flushed from the cross mains without an internal inspection?

The correct answer is based on the established guidelines for maintaining and inspecting sprinkler systems. During an obstruction investigation, it is important to ensure that the system is functioning properly without causing unnecessary damage or disruption.

The guideline that allows for the flushing of a specific amount of scale from the cross mains without requiring an internal inspection reflects a balance between system integrity and the need for maintenance. Flushing half a cup of scale can typically be done safely, indicating that minor debris might be cleared without necessitating a more thorough internal examination of the pipes. This practice helps to prevent larger blockages and potential failures while minimizing the risk of further complications that might arise from insufficient monitoring of the system's internal conditions.

If more than this amount were flushed without inspection, it could potentially indicate larger underlying problems or present a risk of dislodging more significant accumulations of debris, which can lead to more serious blockages or damage within the system. Adhering to the half-cup threshold helps maintain the overall health of the system while allowing for routine maintenance practices.