I'm just about to put a ball valve on my kettle. I thought I'd put a T just before the ball valve which would contain a sight glass. I like the idea, as I only have to make 1 hole in the kettle. I've seen the thermometer/sight glass combos, but taht doesn't interest me, as I'd like to use a remote probe for my thermometer.
So, is there any reason why making a ball valve / sight glass combo is a bad idea?