Troy replaced this burner tube on a Crown AWI. This boiler was 3 years old . We think that this premature failure is the result of poor quality propane gas. We don't see that much of this. Amazingly enough the small hole you see in the middle of the burner caused all of the 6 burner tubes to backfire.
All 6 of these laser cut stainless burner tubes were replaced under a lifetime warranty from Crown.