Was it okay to replace only the turny-part of the faucet supply valve?

Question

I have old galvanized pipes and old supply valves under my sink. I needed to shut them off and turn them back on, and they started leaking, as they do. I went to the store and bought replacement valves, but I just could NOT remove the old ones. They wouldn't budge, and the Internet wisdom says to not DIY with old galvanized pipes. So instead, I took apart my brand new valves, and replaced only the turney-part. Not sure what that part is called. It fixed the leak but I want to know if what I did was okay.

Reason I ask is that I couldn't find only the handle replacement part at the store, it's sold as a whole assembly. I figured if this part is okay to replace ad-hoc, then it would have been sold that way. It made me think twice now.

Answer 1

Yes, it's OK to just replace the "turny part" or valve stem if it stops the leak. It's rare that you've found what appears to be an exact replacement. It's the washer that usually fails and sometimes the valve seat so if your new part stopped the leak then the valve seat is OK.

Yes, it can be tricky working with galvanized pipes. I have known DIY'ers that actually broke old galvanized pipes by torquing it too hard all at once to remove old valves.