Here is a quick question for you, I have a 200gal milk tank that has a vlave on the outlet. the tank side of the valve has what I think is called a tri-clove clamp or something like that. It is 1 1/2". The other end of the valve has some othe type of thread. I get a large nut with a block of plate with it.

SO what and how do I attach say 1" pvc pipe to the outlet. I haven't been able to find anything that fits the treading. I was thinking that I should just take the valve off and get a fitting that goes right in the 1 1/2" tri-clove on the tank.