Re:Why pressure in coolant system?

["Mik's Mail" <miktip@surfnet1.net>]

>Can someone tell me why coolant systems are made to develop & maintain
>pressure in them?

Cooling 101

While driving, your engine creates heat from the combustion taking place
within
the cylinders.  This heat needs to be removed, or the engine would soon cook
itself
into non existence!  Water being an excellent thermal conductor, is used to
control
heat buildup, through a device known as a radiator.  Air flowing through the
radiator
removes heat from the water, allowing the water to reenter the engine at a
lower
temperature the it exited.  The amount of heat removed is inherently built
in to each
specific engine cooling system, and its various components.

Water, in a "pressurized system", raises the boiling point of water.  Water
in a
"liquid state" conducts heat very well.  Water in "gaseous state"
(steam-boiling)
 conducts heat poorly and your engine will cook.  The pressure of the water
is regulated
by the radiator cap.    This is a "balanced system", and any perimeters
exceeding the
capabilities on any component, the system will overheat, and "boil-over".
Or a boil-over
is the radiator cap allowing the pressure to escape before it can damage
components
within  the system.  Cause and effect.

Keep in mind your cars engine is also "air cooled" and "oil-cooled", and the
"water-cooling"
only "helps to regulate" internal engine temperatures.

Auto makers have relied on the pressurized water  technology for many years!
Mainly because its
inexpensive for them to build, and relatively simple to maintain.

Its how Nuclear Reactors are kept cool!

Their are other, "non pressurized" technologies out there, but their
elevated expense hasn't brought them
into "mainstream", and if something works, Why fix it?

So for now were stuck with the old "pressure cooker" system to help keep our
engines cool, and bring us
electricity!

                          Mik