Install the Spirovent® at the point of lowest solubility, which is the place in the system where the temperature is the highest and pressure the lowest. Note as well to always "pump away" from the expansion tank, never towards it.

Related Work

Eastern Illinois University - Charleston, IL
After having tried numerous other methods, the first Spirovent was installed in Carman Hall to deal with a long history of no heat calls and clogging valves.
Higher-Ed Gallery
For almost two decades Spirotherm® has been working with facilities departments to provide solutions for problem systems.
Dirt Separator Piping
Install the Spirotrap® typically ahead of the system component being protected, such as the boiler in this drawing.
Mercy Medical Center - Des Moines, IA
High velocity 18" combination air eliminator and dirt separator.