How often should all foam systems be inspected according to NFPA 11?

Foam systems are vital for fire protection, especially in scenarios involving flammable liquids, and the National Fire Protection Association (NFPA) has established standards to ensure their proper maintenance. According to NFPA 11, which provides guidelines for the application of foam, the frequency of inspection for foam systems is set at annually.

This annual inspection requirement ensures that the foam systems remain functional, reliable, and ready for activation in case of an emergency. During the inspection, various elements are checked, including the foam concentrate, system components, and overall functionality of the system. This proactive approach helps to identify any issues before a fire incident occurs, thereby providing an extra layer of security.

The other options suggest either more frequent or less frequent inspections, which do not align with NFPA 11's standards. Monthly or quarterly inspections may lead to unnecessary operational costs without justifiable benefit, while inspections every two years would not be sufficient to ensure the systems remain in optimal condition to protect against fire hazards effectively. Thus, an annual inspection maintains the right balance of oversight and efficiency in foam system management.