Valve sits about a third of the way up the side of the tank. Looks like it is connected into the tank via a small pipe. Has a Campbell (brand name) gauge head which shows the psi numbers, and sits upon a small rectangular shape body that has the numbers “F938-1” 100 psi max written on it. There appears to be a hex-head nut on the bottom of this “body”, and that is where the water is leaking from. I put my finger there and it almost feels like there is inside threading, it also stopped the leak until I took my finger away. I was unable to locate a missing piece on the floor, so don’t know if something just fell out of this nut.