Thanks for the compliment. I find that graphics like these are the best way for me to work challenges out. I like solving challenges before they become issues. As far as dumping the grey into the black, I have added a dump valve in my system which does just that, see the attached image. In the pipe going from the grey to the black tank, there is a a swing check valve to prevent backflushing of black into grey, then a "T" for the greywater bypass, then a dumpvalve. The dumpvalve can only be used, however, if the black tank is 1/2 full or less, otherwise the tanks level each other out. Best case scenario, I dump excess greywater into the black tank, effectively increasing the size of the grey tank. If I were the lead designer at AIRSTREAM, I would still design at least two tanks, black and grey, I would not combine them. It is a waste of water, to use potable water to flush the black tank. By using the greywater from other larger tanks after dumping the black tank, potable water is conserved. That being said, I would *LOVE* a 50 gallon grey tank, and a 50 gallon freshwater. As it is, I have a 17 gallon black, 17 gallon grey that I added, and a 25 gallon freshwater. The grey tank cost me $400 from www.all-rite.com,
otherwise I'd add an additional one under the floor for freshwater. I've squandered enough of my son's college fund.
Too funny, who's chekcing your math? The attached image should explain a bit more. The tank varies in depth from 7" to 4". Those were exterior dimensions, and the tank is roto-molded, so the sidewalls are approximately 3/8" thick. If you like math, cool, I prefer the tank calculator at: http://www.watertanks.com/calc.asp
Good points. Like you said, the Jabsco is self-priming, so I expect it to act more like a vacuum when it starts to create foam. It is mounted horizontally straight out from the tank outlet, which is the lowest point of the tank, so it should suck out most everything. I built a connection to flush my greywater through the black tank, once the black is emptied. That should clean it up pretty well.
As far as my renderings, I typically 3Dmodel in AutoCAD and Rhino, and render images with Penguin and AccuRender. I do most page layouts and presentations with PowerPoint, and edit my images in PicturePublisher. These are tools I use daily as an architectural designer.