The utility sink has this branch and valve over it.
It's in the rental house. The tenant said it's been dripping and getting gradually faster, and now it's going at the rate of a slow faucet.
Before I just go and cap this thing, I figured I should find out what it's for and if it's needed. At a guess, I'd say it's a pressure relief valve? Working on that hunch, I gradually closed the water main. At no time did the water stop coming out of the valve, though. So if it is a PRV, then either it's not working anymore, or slowly closing the main doesn't effect the pressure enough to change what it's doing.
Any help is appreciated!