Blackwater Tank

okay got it figured out, the gray water does not go to a tank while the black water tank is in the interior right below the toilet.

Thanks for all the replies, I saw your project Westend and I hope I don't have to do that, we shall see. BFL I will have to do a bit more research it seems but that is great info...

"it has a toilet on one side and shower on the other. The floors of both are raised about 4" above the rest, can I assume that it is likely to have a gray water and black water tank? It only has a single dump valve"

No, assume nothing :( The black tank will have a sani-dump on a 3" pipe backed by a 3" drain valve with push pull handle.

Now you have to study the smaller sized pipe(s) going to that for what happens with the grey water. Some older campers have no grey water tank at all. The sink and shower drains just go to the sani-dump cap which has the little extra cap for a hose connection, by-passing the black tank's valve. You put on a garden hose and let your grey go to a nearby ditch or into a bucket that you can then empty somewhere. (Including down your toilet)

Or you may find the grey all drains into the black so you have to do frequent sani-dumps of the one tank. Or there may be a grey tank with its own knife valve and more valves at the sani-dump end so you can dump black first and then sort of flush that with the grey next.

Black and grey tanks do have vents as well as dump valves! If you relocate the tank, besides needing floor plumbing for the toilet (and its water supply line) you need a vent pipe going up through the roof or up the side of the camper outside. The top of the vent pipe has a cover .

I relocated the toilet in my travel trailer. It is a 42 gal tank with a sloped bottom. Since the toilet drain is a gravity system, you will need to be sure that your new stool location is within the tank's boundaries (not a simple job when installing from above and locating close to the tank;s sidewalls) or you will need to relocate the tank. I had a 3" pipe for drain. I cut the hole throug the floor with a 4" hole bit and then stepped down to the correct size hole bit to complete the entry hole into the tank. Online retailer "Tank Depot" sells the necessary tank-pipe gaskets that insure a leak-less pipe-to-tank connection. I closed off the original hole with a shorter length of pipe and a screw cover so that I have access to the tank for a future tank cleaning system or insertion of a cleaning wand if there is a problem. I haven't had any issues to date.

The toilet has to have a straight drop into the black water tank.