A tank of a capacity between 10 gallons and 1320 gallons shall not be placed within how many feet of a horizontally open flame or fuel burning appliance, unless separated by 1 hour fire resistance?

The correct answer to the question is based on safety regulations concerning the placement of fuel tanks in relation to ignition sources like open flames or fuel-burning appliances. The guidelines stipulate that a tank with a capacity of between 10 gallons and 1320 gallons must be located at least 5 feet away from horizontally open flames or fuel-burning appliances unless a one-hour fire resistance barrier is in place.

This requirement aims to minimize the risk of fire hazards associated with fuel tanks. By maintaining a distance of 5 feet, authorities aim to ensure that any potential danger from flames does not escalate into a hazardous situation involving the fuel stored in the tank. The 5-foot separation is a precaution that also takes into consideration the potential heat and flames that could inadvertently ignite the fuel.

In contrast, the other distances suggested do not meet the established safety parameters. The regulations are designed to provide a balance between safety and practicality for installations, with the 5-foot separation being a specific measure that has been determined to effectively mitigate risk.