Yes, what airgunmann said...no loctite needed because the air pressure will keep it on tight. All loctite will do is make it much harder to remove the valve later, which is already hard to do as is with a normal spanner wrench. If you plan on removing these valves with any regularity, I highly suggest getting something like the Saber Tactical Bottle Degasser kit here:
This kit comes in handy when you have to travel with your airguns. TSA requires that the bottles are empty and may ask you to disassemble it to show that it is empty. It has a knurled screw that screws into the bottle and releases the air. Once the tank is empty, attach the red bottle clamp onto...
sabertacticalinc.com
This kit makes it super simple (and safe) to work on your bottles/valves.