When I chopped through my rising main yesterday (yes, it was planned) I
found that the plastic pipe had an o/d of 22mm and an i/d of just 13mm.
After a moment of panic due to not being able to get pipe supports in, I
just pushed it into the fitting (Tectite) and it seems to have made a
good join.

However, I'd like to know what type of pipe this is, and whether my
connection is as good as it seems. If not, what type of connector should
I use instead?

Many thanks

Neil