Can Thermodynamic Processes Occur at Changing Pressure and Constant Temperature?

[Ry122]

how is it possible that processes in thermodynamics can occur at changing pressure and constant temperature and vice versa when the saturated liquid/vapour region on Pv and Pt diagrams are the same? Eg. a substance that begins from the saturated region that reaches critical point in a changing pressure process with constant temperature should be in the critical region on both the Pt and Pv diagrams should it not? but how can that be if temperature is constant and cannot move up into the critical region?

 

[anorlunda]

Your question is unclear. However, I suspect that you may be ignoring moisture suspended in the vapor. As you heat up, more mositure is converted to gas, thus "drying out" the mixture.