Do you need Thread Locker when installing a bottle valve?

FX adds a drop of red loctite to their bottles at the factory, but like others in this thread I have added a bottle valve without it and it was fine.

I wish it was just a drop...had been more like a giant glob in my experience. One of mine had so much on it, it ran into the actual valve itself...that was fun to clean.

But like others said, it's not necessary as the air pressure should hold tight on the threads. I usually put a drop of blue on just for peace of mind.