I should add that I just recon'd my Northern Lights 4.5 genset which had a nice looking SS elbow that I assumed wouldn't give me any issues for a long time......NOT! When I did the recon, I pressure tested the elbow just in case and man....that thing was full of pin holes. Even after I plugged what I could find, it was just too perforated to spend any more time on it. The elbow looked just fine in and out. A lot of stuff can and does happen on the non-service side of the genset that I really got fed up with so I yanked that thing out from its impossible athwart-ships position under the galley and carved a new hatch in my veranda where I can now stand on either side of it. Soon, I'll have cameras there too.
Those of us with Krogens have become familiar with the behavior of SS in our boat applications, including the SS water, waste and fuel tanks that do a good job for quite a while, but sometimes suffer cracks from the lesser-quality welds, mostly due to the rods and techniques of the time not being able to absorb the decades of billowing of the sides from filling and draining tanks.
As a side, I certified in welding in Army Corps training in Ft. Meade in the 90's, and even then we were using exotic rods that did incredible welds on SS and even cast iron that varied in behavior and really needed to be "tuned" for specific applications. I don't think they did much of that in the 70's and 80's, and the base product of the various SS outside of the US, England, Germany and France (even specific grade) was pretty unpredictable in spite of the best intentions of the architects and contractors. I'm glad I don't have to be the guy who rates these materials. Ya gotta start with and weld with known materials. My opinion only.