We figured the easiest way to pressure-test the loops was to do them all at once, with one gauge. We first connected all of open ends with brass "Ts" and connected a pressure gauge. to the last open "T".

We went through a bunch of crimp rings, as each "T" required 3 rings.

Hooking up our air compressor, we charged the loops to 80lbs. and let it sit. After a few hours, the pressure did only dropped 2lbs., then held. We attributed that to the fact that we turned the heat off.

Next, we worked on building and bracing the form to mark the outside edge of the threshold. We're now ready for concrete!