Organization

IAPWS is an international non-profit association of national organizations with objectives to advance the knowledge of the properties of water, steam and aqueous systems, particularly those of industrial importance, and to make the knowledge freely available.

We welcome scientists and engineers with interest in the thermophysical properties of water, steam, and aqueous systems and in the application of such information to industrial uses. 

Our purpose is to connect scientists and researchers with the industry operators, engineers and managers who use their work in an open, collaborative and non-competitive forum. 

IAPWS is based around four working groups and one subcommittee:

• Thermophysical Properties of Water and Steam, TPWS
• Industrial Requirements and Solutions, IRS
• Subcommittee on Seawater, SCSW
• Physical Chemistry of Aqueous Solutions, PCAS
• Power Cycle Chemistry, PCC

Governance is provided by an Executive Committee with representatives from all of the member countries and working groups.

The history of IAPWS dates back to the late 1920s when there was a collective need to develop a better understanding and standardization of the thermodynamic properties of steam to improve the design and performance of steam engines and steam turbines that were being used in transport, factories and electricity production.

• 1929 – Collaboration by a number of countries resulted in the first International Steam Table Conference in London. 
• 1936 - Agreement on a set of “skeleton tables” as the standard for water and steam properties.
• 1967 - Work by an International Formulation Committee resulted in the IFC-67 standard.
  Stakeholders decided that a permanent organization was necessary to manage international standards for thermophysical properties of water and steam. 
• 1971 - The International Association for the Properties of Steam (IAPS) was established by Czechoslovakia, France, Germany, Japan, UK and USSR with annual meetings.
• 1970-1980s – IAPS consisted of ‘A’ and ‘B’ working groups - ‘A’ about thermodynamic properties and developing steam tables; ‘B’ dealt loosely with power plants.
• 1989 - Name change to the International Association for the Properties of Water and Steam (IAPWS) to reflect increased interest in water and aqueous solutions for applications beyond the steam power industry.
• 1990 – Formation of the current four main working groups.

IAPWS meets annually and holds International Conferences on the Properties of Water and Steam at roughly 5 year intervals. The annual meetings are working meetings where attendees are expected to participate and contribute to the development of IAPWS work activities. Members also engage and continue working group activities throughout the year at other IAPWS supported meetings and conferences, webinars and specific task group meetings and calls.

Membership of the working groups is completely open. People do not need to be citizens or residents of member countries to participate.

Anyone interested in IAPWS documents and activities should contact the chairman of their IAPWS National Committee or the IAPWS Executive Secretary for further information.