Expand the pipe-end with a Pipe expander after inserting Carry Nut into the pipe.

Push the expanded pipe to the fitting body all the way into.

Tighten the Carrying Nut by hand for primary biting.

Keep tightening with a common wrench or spanner until Nut edge-face hits the fitting body.

Once the Nut edge-face touches with tightening up-feelilng, it`s the end of Installation!!

Easy to confirm the perfect connection throughout the transparent Nut!!!
Visible check is Available.