Which statement accurately reflects the flushing requirement for foam concentrate portions during service?

Which statement accurately reflects the flushing requirement for foam concentrate portions during service?

• A. All portions must be flushed whenever foam concentrate is present
• B. Those portions of the system normally containing foam concentrate when the system is in service are not required to be flushed
• C. The discharge piping must always be flushed
• D. The foam concentrate storage area must be flushed

Answer: (B)

The key idea is that flushing is used to remove air and contaminants from parts of the system that would not normally carry foam concentrate when the system is in service. The portions that do normally contain foam concentrate while the system is operating are kept charged with concentrate and don’t need to be flushed during service, so as not to waste concentrate and to avoid disturbing the ready-to-proportion system. Because of that, those concentrate-bearing portions aren’t required to be flushed. The other options imply blanket flushing of areas that are meant to stay charged with concentrate or that aren’t routinely flushed, which isn’t consistent with how foam-concentrate portions are managed.

The key idea is that flushing is used to remove air and contaminants from parts of the system that would not normally carry foam concentrate when the system is in service. The portions that do normally contain foam concentrate while the system is operating are kept charged with concentrate and don’t need to be flushed during service, so as not to waste concentrate and to avoid disturbing the ready-to-proportion system. Because of that, those concentrate-bearing portions aren’t required to be flushed. The other options imply blanket flushing of areas that are meant to stay charged with concentrate or that aren’t routinely flushed, which isn’t consistent with how foam-concentrate portions are managed.