Pressure Overpressure Absolute press.		Temperature saturated steam ts °C	Thermal capa- city water h’ kJ/kg	Vaporization- heat r kJ/kg	Thermal capa- city steam h” kJ/kg	Steam volume " m3/kg	Steam density " kg/m3
Pe bar	p bar
The over- pressure relates to an absolute atmospheric ambient) pressure of 1.000 bar.	0,01	7,0	29,34	2485	2514	129,2	0,0077
	0,05	32,9	137,8	2424	2562	28,19	0,0355
	0,1	45,8	191,8	2393	2585	14,67	0,0681
	0,2	60,1	251,5	2358	2610	7,650	0,1307
	0,3	69,1	289,3	2336	2625	5,229	0,1912
	0,4	75,9	317,7	2319	2637	3,993	0,2504
	0,5	81,3	340,6	2305	2646	3,240	0,3086
	0,6	86,0	359,9	2294	2654	2,732	0,3661
	0,7	90,0	376,8	2283	2660	2,365	0,4229
	0,8	93,5	391,7	2274	2666	2,087	0,4792
	0,9	96,7	405,2	2266	2671	1,869	0,5350
0	1,0	99,6	417	2258	2675	1,694	0,5904
0,1	1,1	102,3	429	2251	2680	1,549	0,6455
0,2	1,2	104,8	439	2244	2683	1,428	0,7002
0,3	1,3	107,1	449	2238	2687	1,325	0,7547
0,4	1,4	109,3	458	2232	2690	1,236	0,8088
0,5	1,5	111,4	467	2226	2693	1,159	0,8628
0,6	1,6	113,3	475	2221	2696	1,091	0,9165
0,7	1,7	115,2	483	2216	2699	1,031	0,9700
0,8	1,8	116,9	491	2211	2702	0,977	1,023
0,9	1,9	118,6	498	2206	2704	0,929	1,076
1,0	2,0	120,2	505	2201	2706	0,885	1,129
1,5	2,5	127,4	535	2181	2716	0,718	1,392
2,0	3,0	133,5	561	2163	2724	0,606	1,651
2,5	3,5	138,9	584	2147	2731	0,524	1,908
3,0	4,0	143,6	605	2133	2738	0,462	2,163
3,5	4,5	147,9	623	2120	2743	0,414	2,417
4,0	5,0	151,8	640	2107	2747	0,375	2,669
4,5	5,5	155,5	656	2096	2752	0,343	2,920
5,0	6,0	158,8	670	2085	2755	0,316	3,170
6	7	165,0	697	2065	2762	0,2727	3,667
7	8	170,4	721	2046	2767	0,2403	4,162
8	9	175,4	743	2029	2772	0,2148	4,655
9	10	179,9	763	2013	2776	0,1943	5,147
10	11	184,1	781	1999	2780	0,1774	5,637
11	12	188,0	798	1984	2782	0,1632	6,127
12	13	191,6	815	1971	2786	0,1511	6,617
13	14	195,0	830	1958	2788	0,1407	7,106
14	15	198,3	845	1945	2790	0,1317	7,596
15	16	201,4	859	1933	2792	0,1237	8,085
16	17	204,3	872	1921	2793	0,1166	8,575
17	18	207,1	885	1910	2795	0,1103	9,065
18	19	209,8	897	1899	2796	0,1047	9,555
19	20	212,4	909	1888	2797	0,0995	10,05
20	21	214,9	920	1878	2798	0,0949	10,54
24	25	223,9	962	1839	2801	0,0799	12,51
25	26	226,0	972	1829	2801	0,0769	13,01
29	30	233,8	1008	1794	2802	0,0666	15,01
30	31	235,7	1017	1785	2802	0,0645	15,51
39	40	250,3	1087	1713	2800	0,0498	20,10

·                     Specific enthalpy or Sensible Heat is the quantity of heat in 1 kg of water according to the selected temperature.

Example - Boiling Water at 100 ^oC and 0 bar

At atmospheric pressure - 0 bar gauge or absolute 101.33 kN/m² - water boils at 100 ^oC. 419 kJ of energy is required to heat 1 kg of water from 0 ^oC to the saturation temperature 100 ^oC.

Therefore, at 0 bar gauge (absolute 101.33 kN/m²) and 100 ^oC - the specific enthalpy of water is 419 kJ/kg.

Another 2,257 kJ of energy is required to evaporate the 1 kg of water at 100 ^oC to steam at 100 ^oC. Therefore, at 0 bar gauge (absolute 101.33 kN/m²) - the specific enthalpy of evaporation is 2,257 kJ/kg.

The total specific enthalpy of the steam at atmospheric pressure and 100 ^oC can be summarized as:

h_s = 419 + 2,257

    = 2,676 kJ/kg

Example - Boiling Water at 170 ^oC and 7 bar

Steam at atmospheric pressure is of limited practical use. It cannot be conveyed by its own pressure along a steam pipe to the points of consumption.

At 7 bar gauge (absolute 800 kN/m²) - the saturation temperature of water is 170 ^oC. More heat energy is required to raise the temperature to the saturation point at 7 bar gauge than needed for water at atmospheric pressure. From the table a value of 720.9 kJ is needed to raise 1 kg of water from 0 ^oC to the saturation temperature 170 ^oC.

The heat energy (enthalpy of evaporation) needed at 7 bar gauge to evaporate the water to steam is actually less than the heat energy required at atmospheric pressure. The specific enthalpy of evaporation decrease with steam pressure increase. The evaporation heat is 2,047 kJ/kg according the table.

Note! Because the specific volume of steam decreases with increasing pressure, the amount of heat energy transferred in the same volume actually increases with steam pressure. In other words the same pipe may transfer more energy with high pressure steam than with low pressure steam.

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