Which of the following is NOT a method used to heat oil in storage tanks?

Gas burners are not utilized as a method for heating oil in storage tanks. The primary methods for heating oil in storage tanks include low pressure hot water, steam, and electric heaters. These methods are effective in ensuring the oil remains at a proper viscosity for efficient pumping and burning.

Low pressure hot water heating circulates water through the tank, transferring heat and thus warming the oil. Steam heating utilizes the heat from steam, which can quickly and efficiently elevate the temperature of the oil. Electric heaters, on the other hand, employ electrical elements to generate heat directly within the tank or through immersion.

Gas burners, while they are capable of generating significant heat, are typically not employed in direct contact with oil storage tanks. Instead, they might be used in combustion processes but are not a method for heating oil within the tanks where it is stored. Using gas burners in this manner could present safety risks, including the potential for ignition, making it an impractical choice for heating purposes in storage systems.