Glycol mixture 70/30 initial fill pressure

JHK

In a glycol piping loop for chilled water or a dry cooler (Liebert) do you still want the highest point under 3-4 psig with the pump off or do you want to keep it at a higher pressure at the highest point? 

Jamie Hall

Glycol or not makes little difference. However... be sure that the pressure at the inlet to the pump when the pump is running is also at least 3 to 4 psi.

pecmsg

How many ft to the highest point, top to bottom?

hot_rod

Hopefully not a 70% glycol, 30% glycol mix?
At least 5 psi pressure at the highest point in the system. 10- 12 psi is a common fill for 1 and 2 story buildings.

JHK

Thanks for the replies, I do appreciate it. The height is 18 feet. It is 70% water. 

hot_rod

18 X .433= 7.8 psi to lift water to the high point. add 5 for 12.8 psi at the fill valve. 12 psi is fine.
Most expansion tanks and fill valves come preset at 12 psi. But always confirm the tank precharge.

JHK

Ok, thank you.