Thank you all for the replies, I guess what I am trying to figure out
is why the valve started leaking suddenly. And this rusty water is
also a bit puzzling. To answer your questions - I do have a check
valve and no expansion tank here. I do not think that I need one
because the water heater worked fine for 15 years ( maybe it's getting
old ). I don't think 60 PSI is the problem here. I did lowered the
thermostat setting from 130F to 120F to see if it helps. I will
monitor the valve to see at what point it's leaking.

Thanks again,
GE