A vehicle fuel dispenser installed under a weather shelter must be ventilated and can be enclosed for a maximum of what percentage of its perimeter?

In the context of NFPA 58, the guideline regarding vehicle fuel dispensers installed under a weather shelter requires that these dispensers are ventilated to ensure safe operation and prevent the accumulation of flammable gases. Enclosing a dispenser can restrict airflow and create a hazardous environment, especially if liquid petroleum gas (LPG) is present.

The correct answer indicates that a vehicle fuel dispenser can be enclosed for a maximum of 50% of its perimeter. This allowance for enclosure strikes a balance between protecting the dispenser from weather conditions while not significantly hindering airflow. Adequate ventilation is crucial to minimize the risk of flammable vapors accumulating, which could lead to dangerous situations.

By limiting the enclosure to 50%, the code ensures sufficient ventilation is maintained while still allowing some protection from environmental elements. Maintaining this balance is essential for safety, particularly in preventing potential leaks from escalating into fire hazards.

The other percentages imply a greater obstruction to airflow, raising safety concerns regarding the potential for gas buildup and increasing the risk of fire or explosion. Thus, the 50% enclosure limit is a well-considered compromise in the NFPA guidance for these installations.