valved reflux still

[rkidtech]

Hi still people,
I live in a very remote part of the UK (I'm ot saying where) and I’m in the process of building a valved reflux still. I’m at, if you are familiar with the design, fitting the needle valves to the 2”/54mm reflux cap on the condenser still head base. I’ve drilled two 11mm holes for the ends of the brass needle valves with two nuts on each, one acting as a lock nut to keep the outlet as low as possible in the base of the cap.
To make a distillate tight seal in the hole I was going to use “PTFE” a plumber’s type tape, here in the UK, used on the central heating boiler’s threaded part of the flow and return pipe, compression fittings.
If I where to use this same stuff on the needle valves would this PTFE silicon tape react with ethanol and have adverse effects on any subsequent alcohol that I would produce.
Alternatively I could strip out all the heat sensitive plastic and rubber parts in the needle valves and solder the brass ends flush into the cap. Hmmm. I think maybe I have answered my own question. But what do you guys think?
Geoff