Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Correlation for the Vapor Pressure of Heavy Water From the Triple Point to the Critical Point



Allan H. Harvey, Eric W. Lemmon


A new formulation has been developed to represent the vapor pressure of heavy water (D20) from its triple point to its critical point. This work takes advantage of several developments since the publication of the best previous formulation: the availability of some new data in the lower part of the temperature range, the adoption of the ITS-90 temperature scale, and the adoption of recommended values for the critical constants by the International Association for the Properties of Water and Steam (IAPWS). The new formulation fits the available data within their scatter across across the entire temperature range, and is constrained to pas through the values recommended by IAPWS for the critical point. The previous formulation can be made to provide a similarly good fit if its input temperatures are converted from ITS-90 to IPTS-68 before the vapor pressure is computed. The new formulation offers the advantage of computation without having to perform a temperature conversion.
J. Phys. & Chem. Ref. Data (JPCRD) -


D<sub>2</sub>O, heavy water, ITS-90, vapor pressure


Harvey, A. and Lemmon, E. (2002), Correlation for the Vapor Pressure of Heavy Water From the Triple Point to the Critical Point, J. Phys. & Chem. Ref. Data (JPCRD), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed July 13, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created March 1, 2002, Updated November 14, 2018