A partial case of Phase Equilibrium with two fluid phases staying at Thermodynamic equilibrium.

In other words it's a state of thermodynamic equilibrium between the liquid and gas state of a Fluid Mixture. 

The PT Diagram for Pure Substance will see Vapour Liquid Equilibrium (VLE) as a set of points along a smooth curve ending up with a Critical Point  $//<![CDATA[ \begin{array}{l}(T_c, p_c)\end{array} //]]>$ (see Fig. 1).

The PT Diagram for Fluid Mixture will see Vapour Liquid Equilibrium (VLE) as a closed area with a junction at Pseudo-Critical Point  $//<![CDATA[ \begin{array}{l}(T_{pc}, p_{pc})\end{array} //]]>$ (see Fig. 2).

See also

Natural Science / Physics / Thermodynamics / Thermodynamic system / Thermodynamic equilibrium / Phase Equilibrium / Vapour Liquid Equilibrium (VLE)

[ State of matter ][ Pure substance ] [ Mixtures ][ Fluid Mixtures ][ Phase ]

[ Dew Point Curve ][ Bubble Point Curve ]

[ Critical Point (T_c, P_c) ][ Сritical Temperature T_c ] [ Critical Pressure (p_c) ][ Cricondentherm ][ Cricondenbar ]