for carbon dioxide and water are shown in figure 1. Solid CO2 sublimes when heated. Liquid CO2 can be produced only at pressures above 5atm. Carbon Dioxide: Temperature - Pressure Diagram S a t u r at i o n Li ne. Y-shape, just shifted relative to one another. A phase diagram shows the temperatures and pressures at which the various phases (i.e., solid, liquid and vapor) of a substance can exist. The phase diagram of CO2 is similar to the phase diagram of water: sublimation curve, vaporization curve, triple point, critical temperature and pressure.Of course, the P and T values of are unique to carbon dioxide. Solid CO2 is more dense than liquid CO2. Title: phase_diagram.xls Created Date: 11/10/1999 5:44:57 PM Both phase diagrams for water and carbon dioxide have the same general . phase diagrams.