Water Heaters - water heater drain

After draining my water heater the valve leaks a little, can the valve be replaced? How does the valve attach to the tank? I couldnt tell if it was like a 1/2 or 3/4 fitting or something else. I drain the tank 3 or 4 times a year because I am on a private well and sometimes get quite a bit of sediment in the tank. While repairing the leak can I replace the valve with a ball valve and run a permanent drain line outside instead of the water hose connection.

You should be able to remove the valve by turning it counter-clockwise. You can replace it with a ball valve and pipe it outside. Remove the old one first to check the size. You may need a nipple and then the valve. Good luck.