I have a keg carbonating more often than not, so the valve would be open most of the time if I had one, which kinda defeats the purpose. If you're careful when putting the gas system together, and then take good care of it, you shouldn't have any leaks.
I'm trying to find some porn filmed by a dog wearing a GoPro. - SharonaZamboni
Hunter, when you get bored, will you put a taco in my elephant's hands for me? - Hat