Towel Valve Tails How Can I Stop A New Radiator Valve Tail From Leaking- Help!?

How can I stop a new radiator valve tail from leaking- help!? - towel valve tails

I'm trying to replace a heater with a hot towel. The system uses plastic tubing very flexible, which allows me connect to the radiator and heated towel rails at once in touch, and the dimensions must be removed similarly.

The problem I have with the valve shaft by screws, bolts together, everything seems OK and I use PTFE tape wound in the right direction. Whenever I return to the leaking purge valve, and I am the mother of the valve connect to the queue of the valve. I've tried to do it again a few times, again with a tail, but in vain. The mother does not seem to be the wire or breaking or anything.

This project is my first heat, so I hope someone has some tips on how to get a better seal.