build pages/water system/gray water
10 gallon gray water tank is located under the van floor between the slider door and the exhaust system. Tank is a custom fabricated 14 ga. 304 SS tank sized to utilize the space available. A 80/20 structure supports the tank. On one side the structure bolts to existing holes in the frame rail and on the slider door side into existing holes in the van sheet metal. A 1" OD tube welded on the bottom of the tank is the inlet. A 1" square tube is welded inside the tank is the vent/overflow. The square tube stops 1/2" below the top of the tank.
The sink and the shower pan drain into the tank. The sink drain is a 1" ID rubber hose. Bunch of fittings required to get from sink drain to a 1" hose barb fitting. Used hose clamps at the hose connections. Also made a welded two tee tube from 1" OD tubing that provides the sink drain inlet, the shower drain inlet and a outlet for the 1" hose used to drain the tank. The shower drain is a combination of hoses and a 3/4" copper tube that crosses from one side of the van to the other. 3/4" 90 degree copper elbows are about 1" OD so 1" hose fits the fittings with hose clamps. Shower drain pan has a 1" OD SS drain tube.
A traditional trap is not required at the sink or shower pan. The drain piping goes down below the tank bottom and then back up to the tank. The plumbing path creates a "trap". The tank drain is a simple 1" ID rubber hose with a boat transom expandable plug in the hose. The flexible rubber hose end sits on a flatbar tab below the slider door. To drain the tank the hose is pulled off the flatbar and the plug is removed.