That’s the fresh water tank drain. You’re probably going to need to get a length of vinyl tube to replace the current one, which will be rock hard and not at all plyable, not to mention you’ll cut it so short you won’t be able to attach a new clamp.
At any rate here’s a link to the quarter turn valves. I would replace it while you’re in there, and order a spare to have on hand.
https://www.supplyhouse.com/sh/contr...oduct_id=43030