Reference
Saturated Steam Table
Saturated steam properties at the pressures Indian industrial boilers are actually specified at, in the units Indian plant staff actually read. Computed live from the IAPWS-IF97 industrial formulation, the same standard behind commercial steam tables.
| kg/cm²(g) | bar(a) | T sat (°C) | h_f (kJ/kg) | h_fg (kJ/kg) | h_g (kJ/kg) | h_g (kcal/kg) | v_g (m³/kg) |
|---|---|---|---|---|---|---|---|
| 1.00 | 1.994 | 120.12 | 504.27 | 2201.83 | 2706.10 | 646.34 | 0.8883 |
| 2.00 | 2.975 | 133.24 | 560.22 | 2164.29 | 2724.50 | 650.74 | 0.6106 |
| 3.50 | 4.446 | 147.46 | 621.29 | 2121.55 | 2742.84 | 655.12 | 0.4187 |
| 5.00 | 5.917 | 158.29 | 668.13 | 2087.40 | 2755.53 | 658.15 | 0.3198 |
| 7.00 | 7.878 | 169.78 | 718.23 | 2049.44 | 2767.67 | 661.05 | 0.2439 |
| 8.00 | 8.859 | 174.69 | 739.77 | 2032.64 | 2772.41 | 662.18 | 0.2181 |
| 10.00 | 10.820 | 183.34 | 777.96 | 2002.10 | 2780.06 | 664.01 | 0.1803 |
| 10.54 | 11.349 | 185.46 | 787.37 | 1994.43 | 2781.80 | 664.42 | 0.1722 |
| 12.00 | 12.781 | 190.83 | 811.29 | 1974.64 | 2785.93 | 665.41 | 0.1537 |
| 14.00 | 14.743 | 197.48 | 841.03 | 1949.46 | 2790.49 | 666.50 | 0.1339 |
| 16.00 | 16.704 | 203.46 | 868.02 | 1926.05 | 2794.06 | 667.35 | 0.1187 |
| 17.50 | 18.175 | 207.60 | 886.79 | 1909.43 | 2796.22 | 667.87 | 0.1093 |
| 19.00 | 19.646 | 211.48 | 904.50 | 1893.50 | 2798.00 | 668.29 | 0.1013 |
| 21.00 | 21.607 | 216.33 | 926.71 | 1873.18 | 2799.89 | 668.74 | 0.0923 |
| 24.00 | 24.549 | 222.99 | 957.50 | 1844.33 | 2801.83 | 669.20 | 0.0814 |
How to read this table
- Pressures are gauge, in kg/cm²(g). Absolute pressure is gauge plus 1.0332 kg/cm², using 1 kg/cm² = 0.0980665 MPa and one atmosphere = 0.101325 MPa.
- h_f is the enthalpy of saturated water, h_fg the latent heat of vaporisation, and h_g the enthalpy of saturated steam — the figure that matters for sizing.
- Specific volume v_g is the volume one kilogram of saturated steam occupies. It is what sizes steam piping, and it falls sharply with pressure, which is why high-pressure distribution needs smaller pipe.
Using these figures to size a boiler
The h_g column is where boiler sizing starts. Subtract your feedwater enthalpy from it, divide by 2256.9 kJ/kg, and you have the evaporation factor that converts real steam output into the kg/h F&A 100 °C rating a boiler is actually sold against. The calculators do this for you.
Common questions
Why does latent heat fall as pressure rises?
As pressure rises, saturated water and saturated steam become more alike — the water is hotter and denser in energy terms, the steam is more compressed — so less energy is needed to convert one to the other. At 3.5 kg/cm²(g) the latent heat is about 2122 kJ/kg; at 24 kg/cm²(g) it is about 1844 kJ/kg. Since latent heat is the useful energy in indirect process heating, raising distribution pressure beyond what the process needs means each kilogram of steam does less work.
Should I distribute steam at high pressure and reduce it at the point of use?
Often yes. Specific volume falls sharply with pressure, so high-pressure distribution carries the same mass through much smaller pipe, with lower velocity, lower pressure drop and less radiation loss per unit of heat delivered. The steam is then reduced to process pressure locally, where the higher latent heat is available. The trade-off is that the boiler and the header have to be built and registered for the higher pressure.
What is IAPWS-IF97?
The International Association for the Properties of Water and Steam Industrial Formulation 1997 is the internationally agreed set of equations for the thermodynamic properties of water and steam, used for performance calculations across the power and process industries. It replaced the earlier IFC-67 formulation. The values on this page are computed from it directly rather than interpolated from a printed table.
What is the latent heat of steam in kcal/kg at my pressure?
Read it from the table above at your working pressure. The enthalpy of water in kcal/kg and the latent heat are both given alongside the SI values, because Indian plant documentation is still largely in kcal — and every figure is computed from IAPWS-IF97 at render time rather than transcribed.
What is the difference between saturated steam and superheated steam?
Saturated steam sits on the boiling line: its temperature is fixed by its pressure, and it gives up latent heat at constant temperature, which is what makes it good for process heating. Superheated steam has been heated beyond that point, carries sensible heat with no fixed temperature, and transfers heat far more slowly. This table covers the saturation line.