regulator connection

I have a connector, fixed regulator (150 pounds), and coupler for a CO2 air system. Prior to my tank going out of date and me installing a York on my Jeep, this was my go to for on board air. All that is missing is a CO2 tank which can be purchase online or in my case at he local craft brewery...

Am I correct in thinking there should NOT be a need to use teflon tape on *this* connection from my tank to the regulator? There *IS* a hard plastic washer/gasket in the regulator itself.