In this communication, simple formulas (based on the latest experimental tabulated data) for 11 physical properties of liquid ordinary water substance at saturation state—saturation pressure, density, volumetric thermal expansion coefficient, specific volume of saturated vapor, specific enthalpy, specific heat, latent heat of vaporization, thermal conductivity, dynamic viscosity, Prandtl number, and surface tension as a function of temperature (from 0 to 150℃)—which are used in heat transfer calculations for heat exchangers in heating systems and also for many other technological applications, are presented. Also, the uncertainties of these formulas are given. In most practical cases the pressure of liquid water is within the range from 1 to 10 absolute bar, which makes it possible to neglect the effect of pressure. All properties of saturated liquid water calculated with the recommended formulas are tabulated with a temperature increment of 5°.
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