Yes on ball valves! Best would be ss ball valves. Not terribly expensive considering they last forever. 

We get some that have a little plastic t-handle. They work great for these type applications. You can drill one ear of the t-handle and buy some small aircraft safety wire from Amazon. With the ball closed, wrap it in such a way that it can't pull open without cutting the wire. They work as oil quick-change plugs too for various engines.