Had a project that required me to turn off water to the house. Main shutoff didn't work so had the water company shut it off at the street. Main shutoff is a gate valve. question - Are the inners of a gate valve, I don't know what the correct term would be but, the stem/disc/handle assembly you can screw out of the body commonly or ever interchangeable. I just read that gate valves commonly give out as main shutoffs, so if the whole inner assembly isn't replaceable, is the part that usually gives out replaceable? ie can I just snag another disc of the same size if they're the issue and swap it in there.