What is the minimum diameter of a tank vent opening for tanks with a capacity of 660 gallons or less?

The minimum diameter of a tank vent opening for tanks with a capacity of 660 gallons or less is indeed 1 1/4 inches. This specification is established to ensure proper venting, which is critical for the safe operation of oil tanks. Adequate venting prevents the buildup of pressure or vacuum within the tank, which can occur during filling or emptying processes. Insufficient venting could lead to issues such as leaks or structural failure of the tank due to changes in internal pressure.

The requirement for a vent of this size also helps facilitate the quick and safe dispensing of fuel, as a larger opening allows air to flow freely when the tank is being refilled while also enabling fumes to escape, thereby reducing the risk of hazardous situations.

Understanding the importance of venting helps technicians ensure compliance with safety standards and enhances overall system reliability.