Ullage is defined as which of the following?

Ullage is defined as which of the following?

• A. The volume of cargo remaining
• B. The weight of cargo
• C. The distance from the liquid surface to the top of the tank
• D. The pressure inside the tank

Answer: (C)

Ullage is the space between the liquid surface and the top of the tank—the distance from the liquid’s surface to the tank ceiling. That headspace is the air or vapor space, which is why this option correctly defines ullage. It’s fundamental for calculating how much cargo remains in the tank and for ensuring there’s enough room for expansion, venting, and vapor control during loading, discharging, and changes in temperature or pressure. It is not the weight of the cargo, nor the total cargo volume, nor the internal pressure, so those other choices don’t fit. In practice, ullage measurements help prevent overfill, support safe venting and inerting, and inform cargo calculations by linking the liquid level to the tank’s geometry.

Ullage is the space between the liquid surface and the top of the tank—the distance from the liquid’s surface to the tank ceiling. That headspace is the air or vapor space, which is why this option correctly defines ullage. It’s fundamental for calculating how much cargo remains in the tank and for ensuring there’s enough room for expansion, venting, and vapor control during loading, discharging, and changes in temperature or pressure. It is not the weight of the cargo, nor the total cargo volume, nor the internal pressure, so those other choices don’t fit. In practice, ullage measurements help prevent overfill, support safe venting and inerting, and inform cargo calculations by linking the liquid level to the tank’s geometry.