Larry - I agree IF you have two barriers as in the original unit. Junk is talking about home made after the inspector. If someone decides to braze the two units together and develops a burnthrough it might not be atmospheric and it might wind up being a venturi as the 50 or greater psi water goes sailing by. When many codes require two barriers and atmosphere for potable to solar or radiant, I believe it might be wise to ascertain at least the same level between sewage.

I agree if someone was to braze the whole mess together. Then you don't have two barriers. Two barriers are critical against a potable water supply

Inspectors often have no moral or safety concerns with products, but still are tasked to enforce the code. As a MI (mechanical) inspector myself, I know that the language that held us harmless from prosecution (if we missed something) dissappeared a long time ago.
Therefore like every thing else in this litigeous age, we might like a product, but have to reject it.

A manufacturer is responsible to demonstrate the code worthiness of their product. If I understand the posts, it is this manufacturer's assertion that their product meets code by meeting higher standards. Sorry, products must meet the applicable standards, not just those of their choosing.

j