What is a requirement when installing backflow prevention devices?

The requirement that backflow prevention devices must be located above the highest fixture served is crucial for ensuring their effectiveness. This positioning is essential because backflow preventers work to prevent contaminated water from flowing back into the potable water supply. If a backflow prevention device is installed below the highest fixture, a change in pressure could allow contaminated water to siphon back into the system, defeating the purpose of the device.

By placing the backflow prevention device above the highest fixture, you create a physical barrier that minimizes the risk of backpressure or back-siphonage, which could compromise the integrity of the drinking water. This adherence to installation height is a key aspect of safe plumbing practices and aligns with the standards set by plumbing codes to protect public health.