At http://www.engineeringtoolbox.com/ethylene-glycol-d_146.html the boiling
point of a 50% mixture of pure ethylene glycol and pure water is given as
107.2 deg C but this is at atmospheric pressure at sea level. Antifreeze
also contains other stuff (such as corrosion inhibitors) that will further
increase the boiling point, and at higher pressure the boiling point is
elevated further. I haven't got the required reference materials at hand,
nor do I recall the long ago learned equations used to make the adjustment
for pressure, so let's just say that 120 deg C looks close to the boiling
point. A detailed discussion of antifreeze at elevated temperatures can be
found at http://www.newton.dep.anl.gov/askasci/chem03/chem03987.htm
Also, how accurately is the temperature and pressure known? While the
temperature probably correct to within a few tenths of a degree I suspect
that the pressure is likely to be less accurately known.
Best regards,
Rob Housman
Irvine, CA
Europa XS Tri-Gear
A070
Airframe complete
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of Goff
Sent: Friday, May 29, 2009 11:31 PM
Subject: Europa-List: Boiling Point
Does anyone know the centigrade boiling point of 50/50 glycol/water coolant
in a 912ULS with a 1.2 bar pressure cap ?
We can exceed the 120C maximum on long taxis on hot days but do not seem to
lose any coolant. So at what temperature does it actually boil?
Goff Moore
G-CHOX
Visit - www.EuropaOwners.org
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