Which of the following is necessary when removing an oil tank from service?

Disconnection of the fill and vent piping from the building is a critical step when removing an oil tank from service. This process ensures that no oil spills or leaks occur during the removal and that the system is entirely isolated from any potential fuel supply. By disconnecting these pipes, you reduce the risk of fuel entering the environment and prevent hazardous situations that could arise from pressure or vacuums created in the system.

Additionally, disconnecting the fill and vent piping is part of standard safety protocols and regulations that govern fuel tank removal, ensuring that everything is handled in accordance with local and state regulations. This is vital for maintaining safety and environmental standards during the decommissioning process.