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452 NOTES ON STEAM.
TABLE No. 82. —(Continued).
Absolute
Pres-
sure
in
Pounds
per
Square
Inch.
Temperature
or
Boiling
Point
in
Degrees
F.
Total
Heat
in
B.
T.
U.
per
Pound
of
Steam
from
Water
at
32
Degrees
F.
Latent
Heat
of
Evaporation
in
B.
T.
U.
per
Pound
of
Steam.
Volume
in
Cubic
Feet
per
Pound
of
Steam. Weight
in
Pounds
per
Cubic
Foot
of
Steam.
Cubic
Feet
of
Steam
from
1
Cubic
Foot
of
Water
at
62
Degrees
F.
110 334.6 1183.5 878.3 3.97 0.2521 247
115 338 1184.5 875.9 3.80 0.2628 237
120 341.1 1185.4 873.7 3.65 0.2738 227
125 344.2 1186.4 871.5 3.51 0.2845 219
130 347.2 1187.3 869.4 3.38 0.2955 211
135 350.1 1188.2 867.4 3.27 0.3060 203
140 352.9 1189 865.4 3.16 0.3162 197
145 355.6 1189.9 863.5 3.06 0.3273 190
150 358.3 1190.7 861.5 2.96 0.3377 184
160 363.4 1192.2 857.9 2.79 0.3590 174
170 368.2 1193.7 854.5 2.63 0.3798 164
180 372.9 1195.1 851.3 2.49 0.4009 155
190 377.5 1196.5 848 2.37 0.4222 148
200 381.7 1197.8 845 2.26 0.4431 141
In the preceding table the first column gives the absolute
pressure, which is gage pressure plus 14.7 pounds, or, for
ordinary practice, reckon as 15 pounds. For instance, when
the gage pressure is 80 pounds per square inch, the correspond-
ing absolute pressure is, for all practical purposes, 95 pounds
per square inch, and the corresponding temperature is given in
the second column in the table to be 324 degrees Fahr.
The total number of British thermal units (B. T. U.) re-
quired to convert each pound of water from 32 degrees Fahr.
into steam of any given pressure is given in the third column.
For instance, each pound of water of 32 degrees converted
into steam of 95 pounds per square inch absolute pressure has
received 1180.3 B. T. U.
The fourth column gives the number of British thermal
units (B. T. U.) of heat required to change one pound of water
of the temperature given in the second column into steam of
the same temperature ; which also is the number of heat
units given up by one pound of steam when it is condensed to
water of the same temperature as the temperature of the steam
with which it is in contact. For instance, the table gives the
latent heat of evaporation of steam at 95 pounds absolute pres-
sure to be 885.8 B. T. U.; therefore, if steam of 95 pounds pres-
sure per square inch is condensing into water in a steam pipe
where steam and water are in contact, so that the temperature
cannot drop below that due to the pressure, and the pressure is
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