How should vacuum relief valves be installed according to standard practices?

Vacuum relief valves should be installed in multiples to ensure effective protection against potential vacuum conditions in the plumbing system. This practice is particularly important in applications where a single valve may not adequately address the risk of creating a vacuum due to rapid water withdrawal or changes in pressure. Installing multiple vacuum relief valves allows for redundant protection, as it ensures that if one valve fails or is obstructed, others can still function to relieve vacuum pressure.

Additionally, multiple valves may be necessary in larger systems where different zones or sections require independent vacuum protection. Overall, this approach increases the reliability and effectiveness of the vacuum relief system, safeguarding the integrity of the plumbing infrastructure.