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

I have a Nelson valve that is leaking and I cannot get it to stop. I have Nelson 7900 valves. Over the years I have had several of the valves developed leaks. I have tried replacing the diaphragm alone on some, but this normally does not work. At the suggestion of my dealer, I have started buying new valves and just replacing the "guts" of the valve. This has always worked for me. Well, I just found another leaky valve and this time replacing the "guts" of the valve is not working. I have tightened it as tight as I feel I should. I'm afraid of stripping the threads on the base. The leak is from the valve itself and not the PVC connections. I cleaned around the valve good before replacing. I really do not want to dig up around the box and replace the valve body. Is there anything else I can do to get the valve to stop leaking?

Thats what I was afraid of. Just hoping there was an easier way.