On my Classic Flash I did almost the same as Ali with one slight change. Instead of repeatedly plugging/removing the tube from the ball valve I added the extra part in the picture below. I figured that this would be less likely to wear and, if it did, I could change it in seconds without having to cut or change the tube.

To stop leaks during transportation I used a Festo cap over the end of the part below and, as belt and braces, put a plug in end of the (closed) ball valve.