thanks... is that 3/8 or half inch nipple? im not home and hoping you may know. id rather get everything new.Thats actually how the brass perma seal gets connected to the cga fitting I believe. I have had some issues with mine doing this in the recent months too. You wil need to get the surrounding portion out of the connection to the regulator. You can probably pry it out but you would need be careful not to damage the threads. Worst case you can get a cga-320 fitting and nipple from a welding shop for under $10 for a brass one.
It's just preference I guess. I am lucky enough in that the company that I use to refill/swap tanks with (CeeKay) provides a new perma-seal with every tank I get. They are already screwed in so I never have to mess with it. On a side note, I think its a good practice to check your CGA fitting and also the tank every time you get a new one to make sure that you arent putting two seals together. If this happens it is more than likely that you will drain your newly acquired tank very quickly and almost nothing in this world aggravated me more than paying ~$20 to get a new tank only to have it empty due to reasons that are solely my fault and with a bit more thoroughness, could have easily been averted.What is the big deal with those perma seals? Why not use the crush washers that they give out for free wherever they fill CO2 tanks?