A good ball valve on the main water line is something every house should have. Like many older homes, our house had a tired old stem valve as the shutoff. Not only does this valve take about ten turns to fully close, but ours at least, still leaks a bit when tightened all the way. Ohh and did I mention you need to use a strap wrench to even get the handle to turn? Not something you want to have to deal with in an emergency. Even worse, having to use such a big wrench makes it very likely that you’ll snap the handle right off, and then be left with no way to shut the water off at all.
Theoretically this should be an easy job, shut the water off, cut a section of pipe out, and solder in the new valve. However when you can’t shut off the water completely, it makes soldering in the valve very difficult. Still with a bit of persistence I was able to get it in and leak free. Now with just a quick and easy quarter turn the water is shut off completely.