What is the intent of Section 7.9 of the standard?

• A. To limit system design pressures to not more than 400 psi or within the system component pressure ratings.
• B. To specify maintenance intervals.
• C. To dictate hose coupling types.
• D. To require calculations for friction loss on every run.

Answer: (A)

The main idea here is that Section 7.9 sets a ceiling on how high the design pressure of a standpipe or hose system can be. It requires the design pressure not to exceed 400 psi, or to stay within the pressure ratings of the system’s components if their ratings are lower. This ensures every part of the system—pipe, valves, hoses, and fittings—will be able to handle the pressures it could experience in service, preventing overstressing components and ensuring safe, reliable performance.

Maintenance intervals, hose coupling types, and mandatory friction-loss calculations on every run are addressed by other parts of the code. Section 7.9 isn’t about how often you maintain the system, what couplings you use, or enforcing friction-loss calculations for every run; it’s about keeping the overall design pressure within what the components can safely withstand.