Thanks for the explanation on how the safety valve works. I took it apart just to see and it looked like there was some muck preventing it from closing. It has a little brass piston or valve with a gasket disc on the end. It looks like the only thing that could fail would be the o-rings or that gasket disc. Everything else is brass.
Parts are hard to source for this thing. Seems like there is only one place online from the U.S. and a couple other places are overseas.
Thanks again!