Do you locktite new valves?

Hey guys. Just bought a new valve for the fx bottles from fx. Is like $50 plus $9 shipping. They are limited so they said only 1 per customer. Go get one b4 they run out if you want one. Anyway, do I need to use locktite when installing on the bottle or no? I dont want it unscrew when trying to take the bottle off. Or the pressure would prevent it from unscrewing when taking off from the gun?
 
I wanted a CF bottle upgrade from second hand for my L2, and got one complete bottle from a M3 owner who upgraded to a larger.
I had to make a tool, holding in a vise, and heat up the thread portion, otherwise I could not brake it loose.
FX put in two different colour glue/loctite/whatever. I still have that valve.

Now is my turn to replace the worn threads, pretty hard to remove the bottle... both the bottle female thread and the bottle male adaptor , but my local dealer doesn't have those parts. ETA unknown.