I just inspected this old condo and cant get out of my head the negative slope of the discharge pipe for the TPR valve. I’m intending to call it, but don’t remember if there was a written rule about it.
be installed so as to drain by flow of gravity
https://www.nachi.org/tpr-valves-discharge-piping.htm
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With those old buildings with dedicated (hopefully) TPR discharge lines the “drain by flow” rule is doomed by default. My question is about the “horizontal” part, which actually doesn’t add extra rise, but can allow return of condense (top floor, so no neighbours above).
Emil, no matter about the “horizontal” part, the TPR valve is wrong and needs correction.
Best to you.
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It’s actually a discharge pipe, not a drain pipe, because it’s potentially a pressurized discharge. However, said discharge pipe must drain by gravity. Obviously, the one pictured above cannot.
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…not to mention the reduction in discharge pipe size, eh Bob?
A missile waiting to take off… 
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They coulda’ just screwed this on and skip all the adapters and teflon tape!
Do you think the count down to liftoff would have been shorter? LOL
It takes a while … and then…BOOM!
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This is the air-break where those discharge pipes are ending in the basement. Someone added an AC drain tube.
No air gap there it goes straight into the pipe.
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I stand corrected. This is air-beak, not air-gap.
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I found the code for Quebec in French.
It clearly states that the line must be inclined downward. No surprises here. Thanks for the input.
The section of my report:
Also, it cannot be of reduced size as in picture above.
The discharge needs to be visible. Easy as cutting the discharge pipe short of the lip of the receptor, but the current configuration doesn’t pass muster.
Good eye, sir.
I don’t think there is a specific code about the elbows in the discharge line, but I sure don’t like all those bends. It has to cause some kind of restriction of the discharge. I’d add that to the list of defects.