How must service and hose bibb valves be labeled?

Service and hose bibb valves must be labeled to clearly indicate the fixture they serve. This practice is essential for several reasons. First, it enhances the clarity and efficiency of maintenance and repairs, allowing plumbers and maintenance personnel to quickly identify which valve controls which fixture. This can be particularly important in situations where multiple valves are present and could potentially cause confusion, especially during emergency repairs.

Labeling valves in this way also aids in system troubleshooting. When a fixture is exhibiting issues, having a clear indication of which valve pertains to it allows for quicker isolation of the problem and reduces the time spent diagnosing the issue. Proper labeling aligns with best practices in plumbing and ensures compliance with relevant plumbing codes that emphasize clear identification of components within a plumbing system.

While standard plumbing symbols, location tags, or colored tags could be relevant in specific contexts, the primary objective of labeling is to provide straightforward, useful information about the specific fixture being served, making option B the most accurate choice.