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Old 10-07-2012, 09:57 AM   #109
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Join Date: May 2007
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Originally Posted by dknightd View Post
Glad you are starting to consider expansion of liquid in the system as it heats. That is why there is an expansion tank. System contains "about" 8.4 liters of liquid. The remaining unknown is the volume of air in the expansion tank.
That is not too difficult to guesstimate. If expansion lowers the volume by a factor of 2 (for example, assume .5 mL initial empty space, for 8.4 liters of fill level, the expansion will be about .25mL), at constant maximum operating temperature of 96 degrees Celcius, this relation will apply: P1/V1 = P2/V2. Pressure will be doubled to 2.72 bars... Hah, that justifies the use of a 2-bar cap lol!

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