What is IAPWS 95?

What is IAPWS?

IAPWS is an acronym for International Association for the Properties of Water & Steam. To know more about IAPWS click here.

Click here for information about ASME (American Society of Mechanical Engineers) Properties of Steam Subcommittee.

Useful thermodynamic link is also Thermodynamics Research Laboratory of University of Illinois at Chicago. Where you can see a link to the mirror of this my site.

IAPWS 95

In 1995 IAPWS accepted new formulation for description of Water & Steam thermodynamic properties.

So, all steam tables, formulations etc. issued before 1995 are obsolete now (for example: ASME formulations used for the 5th Edition ASME Steam Tables - NBS/NRC Steam Tables by Lester Haar, John S. Gallagher and George S. Kell Hemisphere Publishing Corporation, 1984 ISBN 0-89116-353-0; The 1967 IFC Formulation For Industrial Use & so on).

Results of calculations with these obsolete formulations may differ heavily from those with IAPWS 95, especially for thermodynamic derivatives.

I'm an author of world first issue of Tables of Thermodynamic Derivatives For Water and Steam based on IAPWS 95 (see position 20 of my List of scientific works ).

Please, feel free to click here to try demo online calculations based on IAPWS 95 for saturation & temperature range from 0.1 to 200 0 C

For full version of IAPWS 95 computational program (whole ranges of pressures & temperatures, both saturation state & superheated steam & subcooled water, SI & USA units etc.) please contact me. There are available very fast (computational speed increased dramatically!) & accurate polynomial approximations of IAPWS 95 in various ranges of pressures & temperatures. These approximations are based on my programs that allow you to fit functions by polynomials of one or two variables on the set of 3 millions of points (!) within only 32 Mb of RAM!