Plumbing Question

[TNJack60]

Just bought an older Coachmen travel trailer. The previous owners used only the city water connection when camping but I wanna be able to use the fresh water tank to camp out in the boonies. Currently the fresh water tank is not connected to the plumbing system for whatever reason I dont know. It has a pipe coming in from the city water connection that goes to the water pump. What do I need and how do i plumb a line from the tank to the water pump?? It has some kind of gray pipe ( pex maybe??) as plumbing. Do I need to just install a 1 way valve and a t fitting to connect the pump and keep the city water on the pump as well??? Or does the city water connection even need to be connected to the pump since it has its own pressure (which I have a regulator on btw). I guess what I'm trying to ask is this: Right now the pipe that comes from the bottom my fresh water tank is disconnected. The pump is about a foot or so away from that line. I need to connect that line to the water pump somehow. What fittings ( i assume a t connector and 1 way valve) do i need to make the connection to the pump?? Hope this makes sense if not maybe I can add a pic tomorrow ( if i can figure out how) of the way it is set up now. Thanks

[srydve]

Here is a link to a good article about rv plumbing, it includes a typical schematic that should help in explaining how everything ties together. Good luck with your project.Water, Water, Everywhere!