Thank you, Larry. I enjoyed reading your article on the history of heating water and liked the many ideas, including that of a u-shaped heat trapping flue. Clearly good design is not the only factor that determines product viability.
A fun movie on this theme was The Man in the White Suit with Alec Guinness in 1951. It’s about a man who discovers a marvelous textile that never soils, never wears out and always looks new. Rather than being seen as a boon to mankind, it is regarded as a dire threat to the economic establishment that must be squelched. At least that’s what I recall hearing about the movie. I’ve yet to see it but been meaning to for some decades now.
Your article mentions metal drain valves being replaced with plastic ones. I recently installed a plastic 3/4″ ball valve on my tempering tank. It was cheaper than a brass valve and looked fine to me. Do you think brass valves are better to use on a water heater?
I appreciate your thoughtful and informative replies.