I have 2 on tank floats. They are on their 2nd year and working fine. I did put them in the freezer overnight last spring and then cleaned with vinegar to remove any scale, then stored them in the freezer in a zip lock bag for the summer. When you first put them on after being stored in the freezer, you will swear they are stuck open. Takes a few minutes of water running through them to thaw the wax that is inside and let the valve close.