The backup line for cooling a flame-impinged tank should be supplied by which arrangement?

The backup line for cooling a flame-impinged tank should be supplied by which arrangement?

• A. A large-diameter line greater than three inches
• B. Placed at the ends of the tank
• C. Established by unmanned nozzles
• D. Supplied by a separate pump and water source

Answer: (D)

Cooling a flame-impinged tank requires a reliable, independent water supply so cooling continues even if the primary system is compromised. The backup line should be fed by a separate pump and water source because this setup provides true redundancy: if the main pump or supply is damaged, the backup can still deliver the necessary flow and pressure to absorb heat, protect the tank shell, and prevent a BLEVE or rapid failure. Relying on a line that shares the same pump or source leaves both lines vulnerable to the same failure, which defeats the purpose of a backup. A dedicated pump and water source also make it easier to control and sustain the desired cooling rate without overtaxing the primary system. The other options—a large-diameter line tied to the same source, positioning at the tank ends, or unmanned nozzles—do not guarantee independent, continuous cooling or effective heat absorption, which is essential in flame impingement scenarios.

Cooling a flame-impinged tank requires a reliable, independent water supply so cooling continues even if the primary system is compromised. The backup line should be fed by a separate pump and water source because this setup provides true redundancy: if the main pump or supply is damaged, the backup can still deliver the necessary flow and pressure to absorb heat, protect the tank shell, and prevent a BLEVE or rapid failure. Relying on a line that shares the same pump or source leaves both lines vulnerable to the same failure, which defeats the purpose of a backup. A dedicated pump and water source also make it easier to control and sustain the desired cooling rate without overtaxing the primary system. The other options—a large-diameter line tied to the same source, positioning at the tank ends, or unmanned nozzles—do not guarantee independent, continuous cooling or effective heat absorption, which is essential in flame impingement scenarios.