Originally Posted by hmmmbeer
its between my shutoff valve and the regulator body. It's hard to explain.
You should have a fiber/nylon washer between the regulator and the tank OR the regulator should have a rubber o-ring in the face of the flange that attaches to the tank.
You should not be using Teflon tape on flared joints. The face of flared joints should mate close enough to form a seal. You can use nylon washers if you choose (I don't have them on mine).
The standard threaded fittings, I usually wrap about 4 times with tape. You shouldn't really have to crank on the wrench to get them snug enough not to leak.