Liquid Water Properties by Temperature and Pressure

Method & assumptions

1. Pure liquid water properties from temperature and absolute pressure, using IAPWS SR6-08(2011) and SR1-86(1992). Supported range: 0.01–110 °C, pressure at or above saturation and no greater than 0.3 MPa (300000 Pa).
2. Calculate the 0.1 MPa reference specific volume and derivatives from SR6 equations 2–3, heat capacity from Table 2, then apply the limited-pressure corrections in Table 4. Density is the reciprocal of specific volume. Table 3 gives expansivity, compressibility and sound speed.
3. Dynamic viscosity and thermal conductivity use SR6 equations 7–8; section 6 permits these temperature correlations throughout the supported pressure range. Kinematic viscosity = μ/ρ, thermal diffusivity = k/(ρ cp), and Prandtl number = μ cp/k.
4. Saturation pressure uses SR1 equation 1. Below-saturation pressure, freezing-range temperatures and pressures above 0.3 MPa are rejected. At saturation, outputs describe the liquid branch, not a liquid-vapor mixture.
5. SR6 reports stable-region uncertainties of about 0.0001% for density, 0.1% for heat capacity, 0.005% for sound speed, 1% for viscosity and 1.5% for conductivity. Extra displayed digits aid reproducibility; they do not imply matching measurement accuracy.
6. Ordinary pure water only. Salinity, glycol, dissolved additives, steam, ice, supercooled liquid and high-pressure service require other property models. This implementation is independently verified against release tables, not certified by IAPWS.

Sources

• IAPWS SR6-08(2011): Properties of Liquid Water, coefficients, pressure corrections and verification Table 8 ↗
• IAPWS SR1-86(1992): Saturation Properties, vapor pressure equation 1 ↗