I also added a 1/4 turn drain to our hot water heater to drain from use to use. I will still pull the entire assembly to drain for storage and flush out debris in the bottom of the tank. To flush I pull the pressure safefy valve so I can flush a greater amount of water through there using a 1/2" NPT to Hose adapter.
Anyway I used a brass 1/2" x Close nipple and a 1/2" x 1/2" quarter turn valve. I removed the compression part of the output and reistalled the nut to turn on the whole assembly. Don't forget to clean out your old teflon tape and install new on the entire nipple.
PARTS FROM LOWES
TIGHTENING UP
VALVE CLOSED
VALVE OPEN
CLEARANCE TO DOOR
