This is a dubious one.
Manufacturers are told they must loctite any removable reg-bottle assembly, to avoid the bottle being unscrewed from the reg when pressurised.
If the reg is screwed into a bottle hand tight and pressurised, then the pressure inside the bottle will keep the bottle firmly fitted to the reg.
The trouble comes when the pressure inside the bottle is so low that it stops being strong enough to hold the bottle against the force needed to remove the system from the marker. This could happen and the bottle may get unscrewed from the reg, rather than the reg from the marker.
Obvoiusly the bottle will then blow off the reg when the thread ends causing damage.
On the other hand, if you loctite the reg onto the bottle to stop this happening. What happens when you need to test the bottle and the reg can't be removed from the bottle. You end up with a 5 year life on the bottle.
The bottle when tested is not only tested for pressure, but also the bottle thread is tested for wear. If the thread is coated with the remains of the loctite, then it will probably fail the test.
I never loctite the bottle to the reg, for this reason. But if i was using a preset, i would make sure i removed the system carefully turning initially from the reg, rather than the bottle.
