How does NFPA 20 treat backflow and cross-connections in fire pump systems?

How does NFPA 20 treat backflow and cross-connections in fire pump systems?

• A. The system must be protected from backflow to prevent contamination of the water supply, with appropriate check valves and isolation as needed
• B. Backflow is acceptable if valves are sealed
• C. No check valves are required
• D. Cross-connections are allowed if the pump is off

Answer: (A)

Backflow prevention and cross-connection control are essential whenever a fire pump is tied into the public water supply. NFPA 20 requires protection so that water from the fire protection system cannot flow back into the potable water supply if pressure in the system changes or if the pump is off. The typical solution is to install a backflow prevention device—often a check valve—with isolation valves that allow testing and maintenance. This setup blocks reverse flow and keeps the drinking water supply safe from contamination that could otherwise be introduced by the fire system. In more sensitive installations, a more robust backflow assembly might be used, but the core requirement is to prevent any backflow or cross-connection into the potable water supply.

Backflow prevention and cross-connection control are essential whenever a fire pump is tied into the public water supply. NFPA 20 requires protection so that water from the fire protection system cannot flow back into the potable water supply if pressure in the system changes or if the pump is off. The typical solution is to install a backflow prevention device—often a check valve—with isolation valves that allow testing and maintenance. This setup blocks reverse flow and keeps the drinking water supply safe from contamination that could otherwise be introduced by the fire system. In more sensitive installations, a more robust backflow assembly might be used, but the core requirement is to prevent any backflow or cross-connection into the potable water supply.