Originally Posted by m sprank
Teflon is not needed.
On a side note:
Teflon tape is not a thread sealant. It is a thread lubricant. The intended use is not to seal the threads, that is what pipe dope, recotor seal, etc. is used for. The teflon tape is to lubricate the threads so that they are more easily separated later. That is why you use teflon tape and a pipe sealant.
Not to be a dick, but that is not correct. PTFE aka teflon tape is a thread sealer, but as with pipe dope etc. should only be used on tapered pipe threads eg BSP threads, where the threads do the sealing.
On a compression pipe fitting, such as Hermito couplings, there is no need for any type of sealant.
You should never use thread tape on lubricating oil lines period.