PSAT_IAPWS

This function calculates the vapor pressure of water as a function of temperature using the explicit IAPWS saturation relation. It is useful for boiling-point and phase-envelope calculations.

The relation is:

P_{sat} = f(T)

where T is temperature and P_{sat} is saturation pressure.

Excel Usage

=PSAT_IAPWS(T)

• T (float, required): Water temperature along saturation conditions (K).

Returns (float): Saturation pressure of water at the specified temperature (Pa).

Example 1: Saturation pressure near room temperature

Inputs:

T
300

Excel formula:

=PSAT_IAPWS(300)

Expected output:

3536.59

Example 2: Saturation pressure near one atmosphere boiling point

Inputs:

T
373.15

Excel formula:

=PSAT_IAPWS(373.15)

Expected output:

101418

Example 3: Saturation pressure at elevated temperature

Inputs:

T
450

Excel formula:

=PSAT_IAPWS(450)

Expected output:

932041

Example 4: Saturation pressure near critical temperature

Inputs:

T
640

Excel formula:

=PSAT_IAPWS(640)

Expected output:

20265900

Python Code

Show Code

from chemicals.iapws import Psat_IAPWS as chemicals_psat_iapws

def psat_iapws(T):
    """
    Compute water saturation pressure from temperature with the explicit IAPWS equation.

    See: https://chemicals.readthedocs.io/chemicals.iapws.html#chemicals.iapws.Psat_IAPWS

    This example function is provided as-is without any representation of accuracy.

    Args:
        T (float): Water temperature along saturation conditions (K).

    Returns:
        float: Saturation pressure of water at the specified temperature (Pa).
    """
    try:
        return chemicals_psat_iapws(T)
    except Exception as e:
        return f"Error: {str(e)}"

Online Calculator

T *

Water temperature along saturation conditions (K).