The "ASME Steam Tables" many people are familar with is a book first published in 1967, with accompanying software in later editions. The thermodynamic properties in the 1967 ASME Steam Tables book were calculated from a formulation for industrial use known as IFC-67, which was developed and adopted as a standard by the international organization that later became IAPWS. The ASME Steam Tables was just one of many books produced from this international standard; several other countries and organizations have issued books based on IFC-67.
However, the IFC-67 formulation is now officially obsolete, having been replaced in late 1997 by a new formulation known as IAPWS-IF97. IAPWS-IF97 is now the international standard for calculations in the steam power industry. As a result, the ASME has produced a replacement for the 1967 book, titled ASME International Steam Tables for Industrial Use. This book has tables based on the new IAPWS-IF97 formulation. They have also produced software based on IAPWS-IF97. The new book and software, described on this webpage, can now officially be considered the "ASME Steam Tables," and they are based on (and fully consistent with) IAPWS standards. Steam tables books based on IAPWS-IF97, and therefore equally consistent with current IAPWS standards, have also been produced in the Czech Republic, Germany, Japan, and Russia.
Neither the ASME Steam Tables nor the IAPWS-IF97 standard should be confused with the separate standard IAPWS maintains "for general and scientific use." The distinction between this standard and the IAPWS-IF97 industrial standard is explained here.
Updated December 1, 2010