I’m somewhat embarrassed that it’s taken me so long to recognize the value of the Flush King.
Flush King Reverse RV Flush Valve, Boxed - Valterra.com (https://valterra.com/product/flush-king-reverse-rv-flush-valve-boxed/)
I also added a flow meter to the valve so I know how many gallons I’m adding for a flush or to charge the tanks.
I feel like I’ve had a valuable epiphany!!
I discovered the Flush King shortly after I bought the LD, and the flow meters a little while later.
For the Class A I owned after the LD I needed a Flush King with a straight clear section. Valterra doesn't make one, and the ones from Camco and others had much lower flow rates. I set about to modify the Camco, and after two tries I succeeded. I'm surprised that in six seasons of frequent use the crude work did not come apart, but hold together it did and thus provided me with a very compact flush unit, picture below.
In posts I've written elsewhere I used the line "Accept no substitutes!," based on my experience. For RVs with outlets on the exterior, the Flush King is the king.
Mark H.
(https://www.lazydazeowners.com/MGalleryItem.php?id=4614)
Twenty-one years ago, I wanted a portable macerator pump kit, but none were available at the time, so I made one.
I had a Flush King that had been useful in our previous LD but did not work well with the gray tank.
The Flush King was cut in half and a threaded insert was glued into it. This provided a connection to the dump outlet, and being clear allowed viewing how dirty the water was, which was useful when flushing.
Macerator pump | Flickr (https://www.flickr.com/photos/lwade/albums/72157602095132874/)
Flush Kings work great on rigs with a straight shot into the holding tanks and give the tanks a good flushing, they do not work well on tanks with long pipe runs to the outlet. For holding tanks with long pipe runs, in-tank flushers are a good addition.
https://www.flickr.com/photos/lwade/albums/72157602104741465/
Larry