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If a lump of ice in a sealed box is steadily heated by air just
a little warmer than the ice's surface temperature, the ice
temperature rises until it approaches its melting point, at which
time, its temperature holds steady and it starts to melt, then
its temperature rise resumes until it boils. This heating with no
temperature rise is called Latent Heat. Then because the container
volume is constant, the pressure starts to rise, and the boiling
temperature rises with it. While there is still water left, the
steam is called saturated, and by knowing its temperature, its
pressure can be read off e.g. from a Steam Table (which is
actually a slim book in size)
If we let a little of this steam escape through a throttle valve,
this steam becomes superheated; that is to say, it is hotter than
saturated steam would be at that reduced pressure.
When all the water has finally evaporated (which takes seven times
the energy to melt ice) further heating superheats the steam.
At this point, knowledge of pressure doesn't necessarily tell
you temperature and vice versa. You can only say that the temperature
can be higher, perhaps much higher, than saturated steam at that
pressure (saturated steam is that which is produced over its water
of formation)
A firefighter may have good reason to be interested in steam,
because this gas has been used as a fire extinguisher in closed spaces.
It has a helpful property: it displaces oxygen and won't support
combustion, it is searching so it fills small spaces without
extensive water damage but it has unhelpful aspects too: it turns
to water vapor in a dense fog cloud which hinders vision and returns
the latent heat needed to initially vaporize it, providing a severe
burning hazard.
212F, more than 1 atm can exist; if the gas is allowed to expand suchthat the pressure remains at 1 atm, there is less steam than that required