How tight should the valve stems be?

[Brian S]

I had a new problem yesterday. TPMS went off after bouncing over the crappy I70 roads around Denver and the mountain roads before. Said a leak. Pulled over and sure enough lost about 10#. Couldn’t see an obstruction so topped it up and cautiously carried on. Alarmed again. Pulled into a repair store, they were too busy to switch to my spare so asked for another top off. As I was measuring pressure I I’m heard air coming out from where the valve stem sits…problem solved. Tightened it up and all good! At the camp site checked all for stems and all were “slightly” loose. Tightened them. Question is, how tight should they be? I did a one, maybe two finger torque as I didn’t want to snap anything. Is that enough? And how to keep them tight? Thanks!!