But the packing around a valve stem can wear out. You may stop the leak as soon as you tighten the nut, but the next time you open and close the valve, be sure to inspect it every hour or so.

To reset the packing washer, simply tighten the packing nut clockwise with an adjustable wrench while the valve is in the "on" position. You should notice as you tighten the nut the drips around ...