Thermodynamic diagram · p–T
Pressure–Temperature Diagram
The liquid–vapor boundary on absolute pressure and temperature axes, generated from the same IAPWS-IF97 engine as the calculator.
How to read it
The teal boundary comes from direct saturation calculations. Its liquid and vapor sides meet at the critical point. Inside the dome, equilibrium liquid and vapor coexist and vapor quality is needed to locate a state. Outside it, the state is single phase. Constant-pressure lines are reference guides, not interpolation tables.
Displayed range
The axes cover common water and steam work rather than every extreme allowed by IF97. A valid calculator result outside the plotted range is reported below the figure instead of being clamped to an edge. Diagram paths use one-decimal SVG coordinates; calculations and exported numbers retain their full stored precision.
Generated with iapws-if97@2.2.0. Methodology and verification.