Funny name… but a very serious feature of some solar pool heating systems!
A “hump jump” in solar pool heat plumbing is when the PVC pipe goes over the roofing cap on a hip roof. The plumbing needs to “jump” over the “hump.”
You may be asking why the two pipes take a different path over the hip. The reason is that the feed pipe (the lower pipe) needs to have a continuous downward path for the solar panels to drain properly when the system shuts down. If the hump jump were to follow the path of the return line, there would be a trap that would keep some water in the panels.
A skilled solar installer will make an aesthetically pleasing hump jump. I’ve seen some ugly ones. Hugging the roofing tile closely requires the use of four fittings and some ingenuity to get the correct angles.