How many inches of vacuum maximum can be lost during a vacuum test conducted over five minutes?

During a vacuum test, the goal is to assess the integrity of a suction system, making it crucial to understand the allowable limits of vacuum loss. A maximum loss of 10 inches of vacuum over a five-minute period is deemed permissible based on industry standards and practices for effective operation of the equipment. This threshold ensures that the system can maintain adequate suction while taking into account potential leaks or performance variations.

If a vacuum loss exceeds this limit, it signifies that the system may have significant leaks or inefficiencies, which can compromise the functionality of fire apparatus while drawing water or other fluids. Thus, maintaining the correct vacuum level is essential for ensuring the reliability and safety of operations during emergencies.