What is the function of a vapor return line in a Stage I system?

• A. To transport recovered vapors from the delivery truck back into the storage tank
• B. To prevent the leakage of liquid fuels into the environment
• C. To facilitate the transfer of fuel from the storage tank to the delivery truck
• D. To enhance the flow of air into the storage tank

Answer: (A)

The vapor return line in a Stage I vapor recovery system plays a crucial role in managing the vapors generated during the fuel delivery process. Its primary function is to transport the recovered vapors from the delivery truck back into the storage tank. When fuel is delivered into the storage tank, vapors are displaced from the tank and must be managed to prevent them from escaping into the atmosphere, where they could contribute to air pollution and health risks.

This line captures the displaced vapors and redirects them back into the storage tank, thereby minimizing vapor loss. This process is essential for compliance with environmental regulations and ensuring the safe handling of fuels. The recovery of vapors helps maintain pressure balance in the storage tank and prevents potential hazards associated with flammable vapors accumulating in the air.

In contrast, the other options focus on different aspects of fuel transfer and environmental protection that do not align with the specific function of a vapor return line. Thus, the correct answer highlights the primary purpose of vapor recovery systems during fuel delivery operations.