Thermodynamic diagram · p–T
Pressure–Temperature Diagram (US Units)
The liquid–vapor boundary on absolute pressure and temperature axes, calculated directly from IAPWS-IF97.
How to read it
The teal saturation curve marks the liquid–vapor boundary and ends at the critical point. Liquid and vapor share the same pressure–temperature coordinates on this curve, so this view cannot show vapor quality. Set quality with pressure or temperature in the calculator.
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@2.8.0. Methodology and verification.