SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

I've got a brass check vale (single) leaking. It leaks at the stem. Assembly seems fine. The valve is not a ball valve type. Instead
it appears more like a faucet. It has a round handle.

Anyway, how do I repair this? I removed the "cap" around the stem but couldn't get the stem to un-thread from the brass
body. I'm afraid too much force will destroy something and will require replacing the whole valve.

For now, I manufactured (band aided) a washer to fit within the cap that seems to have stopped the leak (as long as the valve is
closed).

One last thing, local requirements dictate a double check valve. If a professional repair is needed will this have to be
brought up to code?