Pure body definitions
Saturation vapour pressures of organic compounds

We've just seen that, for any temperature T between the triple-point temperature and the critical temperature, there is one pressure p and one pressure only for which the pure substance is in liquid-vapor equilibrium. These pairs of values (p, T ) describe the vaporization curve.

The vapour pressure of a pure body therefore varies between the triple pressure (p _tr ) and the critical pressure (p _C ).