IAPWS Releases, Supplementary Releases, Guidelines, and Advisory Notes
IAPWS provides recommended formulations for numerous properties of
water, steam, and aqueous solutions. These fall in several categories:
Releases provide carefully evaluated, internationally agreed-upon data
and formulations of properties for which measurements of high quality exist
over a wide range of states. They are intended to embody the state of the art
for representation of the property at the time of the Release.
Supplementary Releases provide supplementary material to
an existing Release, or provide specific (perhaps simpler) formulations for a subset
of the material in an existing Release. They are intended to be of the same
quality as Releases.
Guidelines are similar, but for properties
where the quality or range of the available data is limited.
They are therefore not expected to provide as definitive a representation
as Releases.
Guidelines are expected to require revision when new information is available.
Advisory Notes are documents that give additional information
and guidance that is intended to be useful for users of IAPWS property formulations.
A different type of IAPWS document is the IAPWS Certified Research Need (ICRN),
which is a statement of the need for research on a specific topic.
ICRNs are listed on
a separate page.
An additional type of IAPWS document is the IAPWS Technical Guidance Document,
giving international consensus guidelines on cycle chemistry for fossil and combined cycle power plants.
Technical Guidance Documents are listed on
a separate page.
All current IAPWS Releases, Supplementary Releases, Guidelines,
and Advisory Notes are listed below and are downloadable as PDF files.
While IAPWS does not produce software,
many IAPWS formulations have been implemented in software
produced under the authority of the National Committees of IAPWS member countries;
this page has links to these sources.
A separate document is available describing
obsolete IAPWS recommendations that were issued
in the past but are no longer current.
Releases
-
R18-21:
Release on the IAPWS Formulation 2021 for the Thermal Conductivity of Heavy Water (September 2021)
-
R17-20:
Release on the IAPWS Formulation 2020 for the Viscosity of Heavy Water (September 2020)
-
R16-17(2018):
Revised Release on the IAPWS Formulation 2017 for the Thermodynamic Properties of Heavy Water (September 2018)
-
R15-11:
Release on the IAPWS Formulation 2011 for the Thermal Conductivity of Ordinary Water
Substance (September 2011)
-
R14-08(2011):
Revised Release on the Pressure along the Melting and Sublimation Curves
of Ordinary Water Substance (September 2011)
(This is a minor revision of the 2008 release, which
replaced the corresponding release of 1993)
-
R13-08:
Release on the IAPWS Formulation 2008 for the Thermodynamic Properties
of Seawater (September 2008)
-
R12-08:
Release on the IAPWS Formulation 2008 for the Viscosity of Ordinary Water
Substance (September 2008)
-
R11-24:
Revised Release on the Ionization Constant of H2O
(June 2024)
(This is a revision of the 2007 release)
-
R10-06(2009):
Revised Release on the Equation of State 2006 for H2O Ice Ih
(September 2009) (This is a minor revision of the 2006 release)
-
R9-97:
Release on the Refractive Index of Ordinary Water Substance as a Function
of Wavelength, Temperature and Pressure
(September 1997)
(This release replaces the corresponding release of 1991)
-
R8-97:
Release on the Static Dielectric Constant of Ordinary Water Substance for
Temperatures from 238 K to 873 K and Pressures up to 1000 MPa
(September 1997) (This release replaces the corresponding
release of 1977)
-
R7-97(2012):
Revised Release on the IAPWS Industrial Formulation 1997 for the Thermodynamic
Properties of Water and Steam
(The revision only relates to the extension of region 5 to 50 MPa)
(August 2007) (This is a revision of the 1997 release, which
replaced the corresponding release of 1967).
NOTE: This release has been supplemented by additional
"backward" equations for
p(h,s) in Regions 1 and 2,
T(p,h), v(p,h),
T(p,s), v(p,s) in Region 3,
p(h,s) in Region 3
with auxiliary equations for independent variables h and s, and
v(p,T) in Region 3.
-
R6-95(2018):
Revised Release on the IAPWS Formulation 1995 for the Thermodynamic Properties
of Ordinary Water Substance for General and Scientific Use (September
2018) (This is a minor revision of the 1995 release, which
replaced the corresponding release of 1984)
-
R5-85(1994):
Release on Surface Tension of Heavy Water Substance (September
1994) (This is a revision of the 1985 Release)
-
R2-83(1992):
Release on the Values of Temperature, Pressure and Density of Ordinary
and Heavy Water Substances at their Respective Critical Points
(September 1992) (This is a revision of the 1983 Release)
-
R1-76(2014):
Revised Release on the Surface Tension of Ordinary Water Substance (June
2014) (This is a minor revision of the 1994 revision of the 1976 Release)
Supplementary Releases
-
SR7-09:
Supplementary Release on a Computationally Efficient Thermodynamic
Formulation for Liquid Water for Oceanographic Use (September 2009)
-
SR6-08(2011):
Revised Supplementary Release on Properties of Liquid Water at 0.1 MPa (September 2011) (This is a revision of the 2008 Supplementary Release)
-
SR5-05(2016):
Revised Supplementary Release on Backward Equations for Specific Volume as a Function of Pressure
and Temperature v(p,T) for Region 3
of the IAPWS Industrial Formulation 1997
for the Thermodynamic Properties of Water and Steam
(June 2014) (This is a revision of the 2005 Supplementary Release)
NOTE: This Supplementary Release provides additional "backward" equations
designed to accompany the
IAPWS Industrial Formulation 1997
-
SR4-04(2014):
Revised Supplementary Release on Backward Equations p(h,s)
for Region 3, Equations as a Function of h and s
for the Region Boundaries, and an Equation
Tsat(h,s) for Region 4
of the IAPWS Industrial Formulation 1997
for the Thermodynamic Properties of Water and Steam
(June 2014) (This is a revision of the 2004 Supplementary Release)
NOTE: This Supplementary Release provides additional "backward" equations
designed to accompany the
IAPWS Industrial Formulation 1997
-
SR3-03(2014):
Revised Supplementary Release on Backward Equations for the Functions
T(p,h), v(p,h),
and T(p,s), v(p,s)
for Region 3 of the IAPWS Industrial Formulation 1997
for the Thermodynamic Properties of Water and Steam
(June 2014) (This is a revision of the 2004 Revised Supplementary Release)
NOTE: This Supplementary Release provides additional "backward" equations
designed to accompany the
IAPWS Industrial Formulation 1997
-
SR2-01(2014):
Revised Supplementary Release on Backward Equations for Pressure as a Function of Enthalpy
and Entropy p(h,s) for Regions 1 and 2 of the IAPWS Industrial Formulation 1997
for the Thermodynamic Properties of Water and Steam
(June 2014) (This is a revision of the 2001 Supplementary Release)
NOTE: This Supplementary Release provides additional "backward" equations
designed to accompany the
IAPWS Industrial Formulation 1997
-
SR1-86(1992):
Revised Supplementary Release on Saturation Properties of Ordinary Water
Substance (September 1992) (This is a revision of
the 1986 Supplementary Release)
Guidelines
Advisory Notes
This page updated June 20, 2024
iapws.org >>
Releases, guidelines, etc.