What is this

[01DHS]

This water system is located next to the black and grey water dump. I am assuming these valves have something to do with waste water. But have no idea or information on how they work. This is on a 1995 Land Yacht 30' I just purchased. Does any one have an idea of what this is and how it works.
Thanks.

[A W Warn]

Welcome to the forum!

The valve with the red handle on the left is for outside water, just like your hose bib at home. The device that has been added to this hose bib is a back flow preventer and/or anti-siphon device, so water can't get back into your trailer's fresh water system from your hose.

The capped water connection on the right looks like the flush system for the black tank that was on my 1999 Excella. If it is not your fresh water inlet to the trailer, and you have another place where fresh water hooks up, then my guess is it is the black tank flush system. (not sure if you actually have a flush system but it looks similar to my prior trailer)

[DaveFL]

Not having info on the black hose connection could cause a problem. Manual states black waste valve should be open when connected to water for flushing, good idea to already have the sewer hose hooked up.