Water Saturation Temperature

Method & assumptions

1. Pure water liquid–vapor equilibrium from the triple-point temperature 273.16 K to the critical point 647.096 K. Pressure is absolute, never gauge; temperature input uses kelvin.
2. Uses IAPWS SR1-86(1992), equation (1), with critical temperature 647.096 K and pressure 22.064 MPa. Pressure-to-temperature conversion numerically inverts the same monotonic correlation.
3. The lower pressure input limit is the release table’s rounded triple-point pressure, 611.657 Pa. The tiny interval up to the equation’s approximately 611.657070 Pa endpoint maps to 273.16 K. The upper limit is 22064000 Pa.
4. At 101325 Pa, saturation temperature is approximately 373.1243 K (99.9743 °C). This is equilibrium for pure water, not a boiling-temperature prediction for solutions or transient heating.
5. At a saturation pair, pressure and temperature do not specify vapor fraction or mixture enthalpy. The two densities and reciprocal specific volumes describe separate saturated phases using IAPWS equations (2) and (3), not mixture density. Enthalpy and entropy use equations (4)–(9) and the release reference convention: liquid internal energy and entropy are zero at the triple point, subject to coefficient rounding. Latent heat is the vapor-minus-liquid enthalpy difference. This tool does not calculate steam quality, superheat or subcooled-liquid properties. At the critical endpoint the distinct liquid and vapor phases merge.

Sources

• IAPWS SR1-86(1992): Saturation Properties, equations (1)–(9) and Table 1 ↗