One-Way Valve and Combo Tank

[G Dub]

I'd like to see a discussion on these relatively new valves that allow a one-way flow of fluid through the plumbing. It seems to me that in using these valves one could combine the grey and black water tanks into a single combo tank that holds both grey and black waste water.

When I think about the advantages of a single combo waste water tank, I see how solids would no longer be able to build up as they do in a black water tank. The water from the faucets and shower would work to break up the solid matter. This would mean fewer erroneous readings from the black water tank on your tank level meter.

I think this is a win-win. What do you think?

Please do NOT post about cat boxes (composting toilets). This post is about using water in the plumbing.

Thanks

 

[Rojo-SKO]

I'd be curious to see what these new fandangled one-way valves are that you were talking about. One-way valves or check valves. have been around for a long time if it's the Standard Plumbing ones that I'm thinking of. if everything is going into one tank it's not a "combo tank" it's just one big black tank.

 

[PNW_Steve]

I'd be curious to see what these new fandangled one-way valves are that you were talking about. One-way valves or check valves. have been around for a long time if it's the Standard Plumbing ones that I'm thinking of. if everything is going into one tank it's not a "combo tank" it's just one big black tank.

I saw a bus some years ago that was originally equipped with a single waste tank. After being on the road for a few months the owner redid the waste plumbing and added a second tank to keep grey and black separate.

 

[Rojo-SKO]

Even with traps built into plumbing I would still be afraid that the smell from the tank would back up through the sinks if you had only one tank.

 

[alpine44]

The HEPvO valve is an alternative to a standard, water-filled trap. It takes up less space than a trap and does not dry out over time. Both prevent waste water odors from getting into your living space.

Separating grey and black water is a different issue. In a pinch, grey water could be drained without using a an RV dump station that is designed to treat black water.

 

[Tango-SKO]

I have heard nothing but good things about the Hepvo units from folks using them. Going that route myself. Can save quite a bit of (precious) undercounter space by losing the P-Trap. Mine will actually go beneath the floor in the drain lines.

 

[o1marc]

Even with traps built into plumbing I would still be afraid that the smell from the tank would back up through the sinks if you had only one tank.

Smell can't penetrate if you use a proper P trap.

 

[Tango-SKO]

Unless you park it long enough for the traps to dry out. Seen that happen many times with "occasional" drivers.

 

[Rojo-SKO]

I would think that once the bus has been driven, enough the water would slosh out of the the trap until the next time the sink is used.

Smell can't penetrate if you use a proper P trap.

 

[o1marc]

Unless you park it long enough for the traps to dry out. Seen that happen many times with "occasional" drivers.

I would not keep a black tank full if parked for extended time.

 

[Tango-SKO]

They don't need to be full...to be foul. Best bet is to dump & thoroughly rinse with a deodorant...then top off the P-Traps from time to time with water if parking for any amount of time.

 

[o1marc]

They don't need to be full...to be foul. Best bet is to dump & thoroughly rinse with a deodorant...then top off the P-Traps from time to time with water if parking for any amount of time.

I meant not empty, not necessarily full.

 

[JDOnTheGo]

I can only speak to full-time use but I elected to go with a single waste tank (black/grey). I could not find a real reason not to do this. I've heard the arguments and they make no sense to me. I still wipe my behind with my hand (with paper, of course) so not terribly worried about what some germ-o-phobe might imagine possibly happening one day. Btw, if you've never seen what the goop in the grey tank looks like after a few good days of aging... well... it can be pretty bad (and stinky).

Back to the valves in question: I can't imagine why they would be necessary but I've been guilty of not thinking outside of my tiny little box one or two other times...

 

[G Dub]

I'd be curious to see what these new fandangled one-way valves are that you were talking about. One-way valves or check valves. have been around for a long time if it's the Standard Plumbing ones that I'm thinking of. if everything is going into one tank it's not a "combo tank" it's just one big black tank.

The big difference is the amount of water going into the tank to break up the solids. If you look into it, you'll see that most problems are caused by the solids and not enough water. In this way it is definitely a combo tank. It deserves a different name because of its different performance.

If you're curious about the valve, check it out. I provided enough to get you started.

I'm enjoying the discussion. Thanks to all for jumping in.

G Dub

 

[Tango-SKO]

What he said. Single (black/gray) tank strategy is to dilute the poo with gray water for better evacuation. Some folks plumb the gray so it flushes through the black to try and accomplish the same thing (drain black first then run the gray through as a "rinse").

 

[Mark_In_MA]

I like the idea of separate tanks - I'd feel better knowing that in a pinch, I could dump a little bit of gray water and not have to worry too much about what's in it.

I'd also worry a little bit about the sloshing - I thought black tanks were typically non-baffled, while gray water tanks could be - which means you can put in a much larger gray tank. A 50-gallon tank is 400lbs when full.

Also, if I'm parked for a few days, then there shouldn't be any sloshing going on in the black tank - so I wouldn't want to count on that as a requirement for effective dumping. I'd dump the black first, then flush it with the gray, but not have them connected by default.

 

[Mark carr]

Ok stupid noob question. Ive only gone camping at tent sites with out houses.. Totally new to campers and skoolies. Where does one go to dump a black & grey water tank.

 

[Mark_In_MA]

Ok stupid noob question. Ive only gone camping at tent sites with out houses.. Totally new to campers and skoolies. Where does one go to dump a black & grey water tank.

Most campgrounds (for RVs) have a "dump station" where you go to dump the waste, or there's a truck that comes around and vacuums out your tanks.

The dump station is often just a concrete basin with a manhole cover/pipe that leads into whatever sewer system the campground uses - either a sewer line, septic system, etc. Connect one end of your drain hose to your tanks, drop the other end into the manhole at the dump station, open the valve, and let 'er rip.

 

[Rojo-SKO]

I see the link at the top now, I thought that image was an ad on Tapatalk lol. Neat idea and I think it would be definitely good for smaller builds. I plan on avoiding having a dedicated black tank if I can so this will be useful.

 

[G Dub]

I like the idea of separate tanks - I'd feel better knowing that in a pinch, I could dump a little bit of gray water and not have to worry too much about what's in it.

I'd also worry a little bit about the sloshing - I thought black tanks were typically non-baffled, while gray water tanks could be - which means you can put in a much larger gray tank. A 50-gallon tank is 400lbs when full.

Also, if I'm parked for a few days, then there shouldn't be any sloshing going on in the black tank - so I wouldn't want to count on that as a requirement for effective dumping. I'd dump the black first, then flush it with the gray, but not have them connected by default.

Dumping grey water out on the ground is gross. Don't do it.

You shouldn't be worried, just observant. Know what you tank levels are (which is a big reason to combine - less likelihood of erroneous readings), know where you can dump.

For sloshing to be a safety problem in a skoolie you'd have to have a tank of hundreds of gallons.

Neither tank should be baffled.

Sloshing is good for mixing the waste and more quickly or thoroughly breaking up the solids, but it is not necessary. Water naturally breaks up matter, sloshing or not.

Look into both of my points a bit more and your concerns should be alieved.

Cheers.