Just figured I’d add some content here so I’m just going through old photos/videos.
May I ask for what reason/purpose the two pipes on the right are not connected end to end but rather have endstops and then are connected a bit in?
Are you talking about the ones that are on a loop? That are tied into the rightmost valve? If so those are for a body spray system.
No, was thinking about these joints and endpoints.
Ahh those are just air chambers which are still required in most of the locations that I work.
Aha, never heard of those before. Learned something new today, thanks!
For others in the dark: https://plumbingreview.net/what-is-an-air-chamber-in-plumbing/
The ones that are in the pictures of the article you sent are actually effective, the ones that we use that’s acceptable by code still is just a 12 inch pipe with a cap. They don’t really work though because over time the air pockets full up with water so they basically become useless.