International Association for the Properties of Water and Steam

The International Association for the Properties of Water and Steam

NOW AVAILABLE: Meeting information and registration for the 2025 IAPWS Annual Meeting to be held in Helsinki, Finland, June 22-27, 2025.

IAPWS is an international non-profit association of national organizations concerned with the properties of water and steam, particularly thermophysical properties, cycle chemistry guidelines, and other aspects of high-temperature steam, water and aqueous mixtures relevant to thermal power cycles and other industrial and scientific applications. IAPWS objectives are

To provide internationally accepted formulations for the properties of light and heavy steam, water and selected aqueous solutions for scientific and industrial applications. (Official documentation of these formulations is under the Releases and Guidelines section of this website)
To provide technical guidance, obtained by international consensus of experts, on cycle chemistry and technology for steam power cycles in fossil and combined cycle plants and other industrial applications. (These are expressed in IAPWS Technical Guidance Documents)
To define research needs and promote and coordinate research on steam, water and selected aqueous systems important in thermal power cycles
To collect and evaluate the resulting data, and to communicate and promulgate the findings
To provide an international forum for exchange of experiences, ideas and results of research on high-temperature aqueous media

IAPWS is organized as an association of member countries (or groups of countries). An Executive Committee, consisting of the official representatives of all members, conducts the general business at an annual meeting. IAPWS is governed by a set of Statutes and Bylaws. Note that IAPWS does not endorse or promote commercial products or entities; see the By-Laws for restrictions on the use of the IAPWS name and logo for commercial purposes.

Interested individuals, whether or not they reside in a member country of IAPWS, are welcome to participate in the various IAPWS Working Groups.

Current Members are Australia, Britain and Ireland, Canada, Czechia, Germany and Switzerland, Italy, Japan, New Zealand, Nordic IAPWS (Denmark, Finland, Norway, Sweden), Russia and the United States, plus Associate Members Argentina & Brazil, China, Egypt, France, Greece, India, Israel, and the Netherlands.

President:	Monika Nielsen, Ørsted, Fredericia, Denmark, e-mail: moneb@orsted.com
Executive Secretary:	Dr. Daniel G. Friend, Boulder, Colorado, United States, e-mail: dg.friend@iapws.org

This page updated June 3, 2025