This is a very common piping detail and available on purveyor's websites.
It is also available in ASHRAE Systems volume.
Glycol mix just takes the place of domestic water fill with a pump adding the pressure to fill the system. Pump will shut off when pressure stat reaches set-point.
Pressure is about 6 psig/floor (12' floor-to-floor) of building plus 5 psig extra for venting.