What is the role of gravity displacement in steam sterilization?

Gravity displacement is a method of air removal used in some steam sterilizers. In these sterilizers, steam is introduced into the top of the chamber, and as the steam fills the chamber, it forces the heavier air out through a vent at the bottom. Gravity, therefore, assists in the displacement of air. This method relies on the density difference between steam and air. Steam is less dense than air at sterilization temperatures, causing the air to settle at the bottom of the chamber. Gravity displacement sterilizers are typically used for sterilizing liquids and heat-stable items that do not have complex geometries or lumens. While effective, gravity displacement is generally slower and less efficient at air removal compared to prevacuum sterilizers, which use a vacuum pump to actively remove air from the chamber.