Watering system tube

[amon]

I checked the edstrom website and the 3/16" is the Inside diameter.

I use the larger blue lines myself 5/16". To make it work with the 3/16" barb on the vari-flow valves you need a 1" piece of 3/16 and it fits snug inside the 5/16" tube.

Thanks. I think I know how to make it works now.