Seeking advice on calculating the required pump size for a hydro test on a coil system

[t_me]

I'm conducting a hydro test on a coil system and need guidance on determining the appropriate pump size. The objective is to pump water through the coil with a flow rate sufficient to eliminate air pockets that tend to form at the top of the coil. (see yellow below)



Here are the essential details about the coil:

• The inlet and outlet of the coil are at the same height, 1 meter off the ground.
• Outer Diameter of the pipe: 75mm
• Inner Diameter of the pipe: 70mm
• Diameter of the coil: 1m
• Length of the coil: 3m

Based on a simulation, it's evident that a sufficiently high flow rate can remove all the air from the system. Can anyone advise on how to calculate the required flow rate to achieve this goal? I also want to ensure that the coil remains entirely filled with water throughout the process. Any insights on making this calculation better and more concise are welcome. Thank you!