What am I looking at on this water heater??

Inspection yesterday turned up a lot of head scratchers, but I might have lost hair on this one. I used HG to help explain the pictures for you. If anyone can explain what is going on here, please do. I know I am writing it up in the report, but does anyone know what they were attempting here? I tried to google it but nothing even close came up. TPR comes out the top, has a T before the valve, the T connects a pipe, which turns into a bigger pipe with capped T’s coming off it, then back to a smaller pipe, then connects to the tank drain on the bottom. That was hard to type. Here are the pictures. I hope they don’t turn sideways on me as they have been lately.

Go to your other post for answers.

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