Steam Properties Calculator - Saturated & Superheated Steam Tables

How It Works

1. Select Lookup Mode

   Choose saturated steam by pressure, saturated steam by temperature, or superheated steam. For most boiler and steam trap work, saturated steam by pressure is the starting point. For process heating calculations involving superheated steam, use the superheated mode.

2. Enter Absolute Pressure or Temperature

   Enter the steam pressure in PSIA (or kPa absolute in SI mode), or the temperature in degrees F or C. The tool does not convert gauge pressure: if you are reading a gauge, add local atmospheric pressure (about 14.7 psi at sea level) before entering the value.

3. Review Saturated Properties

   For saturated steam, the output includes saturation temperature (Tsat), specific enthalpy of liquid (hf), enthalpy of evaporation (hfg), enthalpy of saturated vapor (hg), specific volume of liquid (vf) and vapor (vg), and entropy values (sf, sfg, sg). These are the building blocks for steam system calculations.

4. Superheated Mode (Approximate)

   For superheated steam, enter pressure and a temperature above saturation. The tool returns approximate enthalpy, specific volume, and entropy using a simplified model (not IAPWS-IF97). The app flags these results as estimates and warns that error depends on the state point.

5. Apply Results With Review

   Use enthalpy values as inputs to heat transfer rate math (Q = m x delta-h), boiler efficiency checks, flash steam estimates, and steam trap sizing work done outside this tool. Use specific volume to convert mass flow to volumetric flow. Verify against certified steam tables before design reliance.

Built For

• Boiler operators checking steam properties for daily log entries, efficiency calculations, and trend analysis
• Stationary engineers pulling property values for steam-trap sizing work done outside this tool
• Process engineers calculating heat duty for steam-heated heat exchangers, reboilers, and jacketed vessels
• Plant maintenance techs verifying deaerator operating temperature against saturation tables to ensure proper oxygen removal
• Energy managers hand-checking flash steam recovery questions from high-pressure condensate to lower-pressure systems
• Mechanical engineering students verifying thermodynamic cycle calculations against published steam table values

Features & Capabilities

Saturated Steam Tables

Saturated steam properties from 0.089 psia (triple point) to 3,200 psia (critical point), interpolated linearly between 31 rows reconciled to IAPWS-IF97 and NIST reference data. Returns Tsat, hf, hfg, hg, vf, vg, sf, sfg, and sg.

Superheated Steam Estimate

Enter pressure and temperature above saturation to get approximate superheated enthalpy, specific volume, and entropy from a simplified model (not IAPWS-IF97). The app flags high-pressure and near-critical results.

Imperial and SI Display

Temperature in Fahrenheit or Celsius, absolute pressure in psia or kPa, enthalpy in BTU/lb or kJ/kg, specific volume in ft3/lb or m3/kg. Conversions use NIST SP 811 factors.

Disclosed Source Boundary

The app states exactly what its table covers (saturation range only, absolute pressure, no quality/flash/compressed-liquid modeling) and lists the residual items to resolve with certified steam tables and qualified review.

Quick Reference Table

A built-in table of key saturation points from 212 to 600 degrees F for fast sanity checks against your plant gauges and logs.

PDF Export

Export steam property lookup results - including the source warnings and residual gaps - as a branded PDF for boiler logs, engineering calculations, or training documentation.

Assumptions

• Saturated table rows up to 650 degrees F computed from IAPWS-IF97 (regions 1/2/4); 675/700 degrees F rows from NIST WebBook (IAPWS-95); final row is the IAPWS-95 critical point (705.1 degrees F, 3,200.1 psia)
• Saturated properties are linearly interpolated between 31 table rows along the liquid-vapor saturation curve
• Superheated mode uses a simplified approximation: h = hg + Cp x (T - Tsat) with a compressibility-corrected ideal gas for specific volume; it is not IAPWS-IF97
• Pressure inputs are absolute (psia, or kPa absolute in SI mode); no gauge-to-absolute conversion is performed
• Units follow the classic US steam-table IT-BTU convention (1 BTU/lb = 2.326 kJ/kg exactly)
• Enthalpy reference point is saturated liquid water at the triple point (32.02 degrees F, 0.0887 psia)

Limitations

• No steam quality (wet steam) input: outputs are saturated-liquid, saturated-vapor, or approximate superheated states only
• No flash steam calculator: flash percentages must be worked by hand from the hf/hfg values (see the FAQ)
• Does not cover the compressed liquid (subcooled water) region below the saturation curve
• No output above the critical point (3,200.1 psia, 705.1 degrees F); supercritical states are out of range by design
• Superheated approximation error depends on pressure, temperature, and distance from the critical point; the app flags high-pressure results
• Does not calculate steam flow rates, pipe sizing, steam trap sizing, or pressure drop through valves and fittings
• Does not account for dissolved gases, water treatment chemicals, or boiler carryover effects on steam properties

References

• IAPWS R7-97(2012) - Industrial Formulation 1997 for the Thermodynamic Properties of Water and Steam - source pointer
• NIST Chemistry WebBook - Thermophysical Properties of Water (IAPWS-95 saturation data) - source pointer
• NIST SP 811 Appendix B.8 - unit conversion source pointer
• ASME Steam Tables / NIST SRD 10 - certified verification path for design work
• ASME Boiler and Pressure Vessel Code, Section I - Power Boilers - source pointer only
• Babcock & Wilcox, Steam: Its Generation and Use - industrial boiler operations reference

Frequently Asked Questions