I had to replace my black water tank on a previous TT. Don't ask how it happened (Darn stump and YUCK!!).
Anyway. All ports entering the tank were glued. Tanks are generic and I had to drill out the holes where I wanted to put new fittings. These I had to glue in. I ordered the fittings, primer and glue with the tank. Although you can purchase the glues at the hardware store, I wanted to make sure I had the right stuff for the tank. It seemed to be thicker than reqular PVC/ABS glues.
The rest of the drain pipes were glued, I had to cut them off and add couplers to install the new tank.
NEW - - 2017 Shasta Phoenix 33ck
OLD - - 2007 Forest River Wildwood 312BHBS LA
Still Running - - 2008 F350 CC Lariat 4x4 6.4 Diesel