Water knife idea for black tank?

[TaliaDPerkins]

I'm wondering it is advantageous to have a filtered line from the gray (or fresh) water tank to permit a high pressure nozzle to jet diagonally into the black water tank, purpose being to macerate contents?

[Jolly Roger bus 223]

illegal buy every plumbing code including canada unless you have a backflow preventer that is supposed to be certified every year.
or a dual check valve to to prevent cross contamination.
i have an idea in my head of your fancy tank set up to do it with your idea but plumbing grade on your tank and the lines in and out should not require what you are questioning.
a black tank creates solids that could be a problem if you use a low water flow fixture

[TaliaDPerkins]

Yes, check valves. Knew about those.


Wondering about whether there is much of an advantage to not just flushing the grey tank through the black tank, but attempting to macerate the black tank contents with a water jet.

[Danjo]

I got the place that made my black tank to install a jet fitting that I have connected to a water spigot fitting via a valve and some PEX. If I have a hard time getting the tank to drain I can connect it to the hose at the dump station and give it a jet cleaning. I haven’t had to use it yet.

[Ronnie]

I have not had any trouble draining the black tank either, and we only have the 2" cam lock coupler not the 3" hose most rv's use.


What we have found is in another application, a railroad car used by the public it did clog once in 10 years of use with toilet paper. So toilet paper meant for rv black tanks, or septic systems does help with that. Regular tiolet paper is a bit to strong and does not fall apart enough if enough of is in there. This car does also use the 2" cam lock. Mainly because the potti potty company uses that size fitting and hose.

[turf]

don't put ideas like this in my head.



ok, you want to stir the pot before dumping.
connection to freshwater is unsanitary.
you should just reuse the waste water.

get a macerator pump and a tank cleanout adapter.
plumb the output of the pump into the sprayer of the cleanout adapter.

https://www.ebay.com/i/152541108022?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=152541108022&targetid=93506506774 7&device=c&mktype=pla&googleloc=9028965&poi=&campa ignid=10829254305&mkgroupid=109722609074&rlsatarge t=aud-622524042958la-935065067747&abcId=9300396&merchantid=110590849&gc lid=Cj0KCQiAwf39BRCCARIsALXWETyA4_TRrr2NPr1BBLCmrm-RBx5pwo689kyevflWEM-2bMSuRIxjDvYaAo5iEALw_wcB

https://www.etrailer.com/RV-Sewer/Va...YaAphDEALw_wcB

you can combine those, hook it up to your tank, grind the contents and then serve a mean milkshake when you are done.



easier would be to have a macerator toilet