ASME CRTD-83-2006 — ASME Steam Tables, Compact Edition (IAPWS-IF97)

📖 ASME CRTD-83-2006 is the ASME Steam Tables Compact Edition, prepared by the Properties Subcommittee of the ASME Research and Technology Committee on Water and Steam in Thermal Systems. It provides the thermodynamic properties of saturated water and steam and of superheated steam in both U.S. Customary and SI units, computed entirely from the IAPWS-IF97 Industrial Formulation 1997 adopted by the International Association for the Properties of Water and Steam (IAPWS) for industrial use. It is the everyday look-up reference for turbine, boiler, and thermal-system design and operation. More comprehensive tables and charts from the same formulation are published in ASME International Steam Tables for Industrial Use (ASME Press, 2000), and implementing software is available from ASME as ASME Steam Properties for Industrial Use.

1. Contents and Structure of the Tables 📋

The compact edition is organized in two unit systems with six main tables, plus unit conversion factors and Mollier diagrams:

• U.S. Customary units: Table 1, saturated water and steam (temperature table); Table 2, saturated water and steam (pressure table); Table 3, superheated steam (1 to 15,000 psia).
• SI units: Table 4, saturated water and steam (temperature table); Table 5, saturated water and steam (pressure table); Table 6, superheated steam (0.005 to 100 MPa).
• Unit conversion factors and Mollier diagrams in both U.S. and SI units.

For saturated states the tables list temperature/pressure, saturation pressure or temperature, specific volumes (liquid v_L and vapor v_V), enthalpies (liquid h_L and vapor h_V), and entropies (liquid s_L and vapor s_V); the superheated-steam tables give complete superheated properties — volume, enthalpy, entropy — on a pressure-temperature grid.

2. Reference State 🧭

By convention, the specific internal energy and specific entropy are defined to be exactly zero for the liquid phase of water at its triple point. This reference state agrees with IAPWS international convention. Always use the same datum when working with the tables, and convert before comparing with older tables built on a different reference, otherwise enthalpy- and entropy-difference calculations will be in error.

3. Saturated Steam Properties: A Sample 📊

The table below excerpts typical rows from Table 1 (U.S. temperature table) to illustrate how saturated water and steam properties vary with temperature: saturation pressure rises rapidly, the vapor specific volume falls sharply, and the latent heat of vaporization (h_V − h_L) gradually decreases.

4. Superheated Steam and the Mollier Diagram 🔥

The superheated-steam tables (Tables 3 and 6) provide specific volume, enthalpy, and entropy on a pressure-temperature grid, used for turbine stage calculations, piping pressure-drop work, and thermal-cycle analysis. The Mollier diagram plots enthalpy (h) against entropy (s) with isobars, isotherms, quality lines, and isochores, and is the most intuitive tool for hand analysis of throttling and expansion processes. Separate U.S. and SI Mollier diagrams are provided — always use the diagram matching the unit system of the data tables.

5. Engineering Practice Essentials 🛠️

• 📐 Keep unit systems consistent: U.S. Customary and SI data must never be mixed; state the unit system in every engineering document.
• 🧭 Keep the reference state consistent: confirm the enthalpy/entropy datum (triple-point liquid zero) before comparing with software or older editions.
• 📈 Saturated vs. superheated: decide whether the state is in the saturated or superheated region, then select the corresponding table; two-phase states require quality interpolation.
• 🧮 Cross-check with software: verify hand look-ups against IAPWS-IF97 software such as ASME Steam Properties.
• 📚 Companion references: for finer grids and complete charts, use ASME International Steam Tables for Industrial Use.

6. Frequently Asked Questions ❓