The thing with a fitting like that is that its prob not the valve itself that would fail (dezinc enough to become weak). Its far more likely that the threads on the skin fitting which is the thinnest part would fail first or the threads in the tails. It is extremely difficult to tell condition from the outside like that, so if it was mine, on next lift out, I would dismantle and inspect for pinking and if in any doubt, for what they cost get a new DZR set from ASAP supplies and replace.
