Dual Dump Setup: Macerator & Gravity Dump

[peteco]

I have purchased a 4-leg wye and modified one leg to take a standard sewer hose and cap. This 4-leg wye is on the newer Roadtreks, but has a threaded plug for emergency tank draining. I modified this leg, because I thought unthreading the plug would be a very messy event. This leg will have an RV drain cap with a small garden hose fitting. I think the garden hose fitting cap can be removed quickly and drain hose attached to drain off the liquid. I am waiting until I need to service the pump before replacing the existing 3-leg wye.

I am curious what others have done, particularly Booster as you have mentioned a dual dump system in your macerator topic.

Thanks,

Pete
2006 Roadtrek 210 Popular

[booster]

I am trying to take the dual dump setup to a true dual that you can use either the pump or gravity without any changeover that is more than normal use.

Our 07 has the same 4 way tank/valves fitting that you got, with the threaded plug in the outboard 2" leg. I may put a valve on that leg as long as I have it all off, aimed at 90*, but don't intend on really using it for dumping under any case.

Right now it looks like I will use the 4 way as is, with the same rubber coupling on the outlet of the 4way. Stock, the next fitting is a reducer to 2", then a rubber coupling, then the pump. We will have, instead of the reducer, a 3" wye fitting that one leg goes straight through to an added 3" valve and a then a standard gravity dump system over to the drivers side of the van. The other leg of the 3" wye will angle to the front, then use the 2" adapter to a 45* fitting, then the rubber coupling and pump. The pump outlet will go to the stock hose setup we have now.

The macerator setup should work exactly like stock does now.

If the pump fails, all you would need to do to gravity dump would be to extend the gravity hose and open the added valve. It would then be just like a factory gravity dump setup.

If it all works, out, it should be very versatile.

I have nearly all the parts on hand now, but still need the extra valve and hubs, gravity hose and tube, and need to make the new mountings.

I would guess it should be all done in 2-3 weeks when all of it gets here, and I will get a full set of pix put up on the forum.

[Davydd]

Are you installing a blade slide valve with your gravity dump? It is best to have a bayonet cap that you can take off then hook up your 3" slinky hose before opening the valve. I don't know if it will help your particular situation but you ought to go out to Lake Region RVs and look at a new Great West Van. They are set up to dump via macerator or their traditional gravity way.

http://www.campingworld.com/shopping/it ... seals/6382

[avanti]

You guys do know about this fitting, right?

[booster]

Originally Posted by Davydd

Are you installing a blade slide valve with your gravity dump? It is best to have a bayonet cap that you can take off then hook up your 3" slinky hose before opening the valve. I don't know if it will help your particular situation but you ought to go out to Lake Region RVs and look at a new Great West Van. They are set up to dump via macerator or their traditional gravity way.

http://www.campingworld.com/shopping/it ... seals/6382

Yep, the intent is to have a 3" slide valve before the slinky connection. I also hope to be able to leave the slinky connected all the time similar to the gravity dump Roadtreks used to do, with the slinky self-storing inside a larger rigid tube that hinges down to come out under the low skirting when needed. The bayonet cap would go on the end of the slinky.

My largest concern would probably be how often the extra valve would have to be "exercised" to make sure it doesn't stick too badly. Hopefully, a flush of both systems at the end of trips will be plenty.

[booster]

Originally Posted by avanti

You guys do know about this fitting, right?

That is the 4 way fitting double valve setup that is in our Roadtrek and will remain in place. It is probably the one Peteco has also that he is going to put in. The stuff I am adding and moving goe right after that fitting.

The cleanout, or emergency dump, would be the 2" port on the outboard side. It is nearly impossible to get an easy connection into the port, at least on a Chevy 190, and I think impossible to get a decent valve there, so emergency dumping would be a pain. You would have "water" on the ground every time you hooked up, to some extent.

I am sure ours will be a bit of overkill, but as long as I was at it, I wanted to see if true dual capability was possible, and practical.

[peteco]

Yes, that is the 4-way fitting I have. I modified the emergency clean out leg to take a standard RV sewer fitting. I have not installed it yet so I hope it fits.

Pete
2006 Roadtrek 210 Popular

[avanti]

Originally Posted by peteco

Yes, that is the 4-way fitting I have. I modified the emergency clean out leg to take a standard RV sewer fitting.

I guess I am confused by what you mean by "a standard RV sewer fitting." Isn't that (a bayonet connector) what the downward-pointing branch is? [not arguing, just curious].

[booster]

Originally Posted by peteco

Yes, that is the 4-way fitting I have. I modified the emergency clean out leg to take a standard RV sewer fitting. I have not installed it yet so I hope it fits.

Pete
2006 Roadtrek 210 Popular

There is very little space for anything on the cleanout side, at least on our 07 Chevy 190. The only real space you have is to the rear of the van, as the grey tank is cut away there, so you would need a 90* right out of the cleanout, and then another 90* pointing down. The 3" hoses are pretty big and probably wouldn't work very well, but you might get by with a 2".

I just came in from the shop after getting the van higher and level, so I can get a good check on road clearance for however I wind up doing it. Right now it looks like if I make my own adapter fitting to the pump, I many be able to move it all the way to the passenger frame rail, parallel with the grey tank valve.

I will run out and take a picture of the fitting you have and the room around it, as ours is still in place.

[booster]

Here is picture from below of the area in question. This fitting has the Roadtrek installed threaded bushing so it sticks out about 3/4" or so further than just the hub would.



Without the threaded bushing to the female hub edge is about 3"

There is about 3/4" above the hub to the tank

It is about 7" from the centerline of the hub diameter to the tank, to the rear.

Most of the fitting is higher than the bottom of the tank, some hangs below, but not much

One big problem could be that this is the lowest road clearance on the van, so whatever you do can't be more than about 3/4" below the hub bottom (even with the big valve), or it will likely get hit, if it is permanent.

If I were to use this spot, I think I would use a glue in 2" elbow to the fitting aimed to the rear, a little pipe to the rear, and a 2" elbow pointing down, with a threaded bushing in the elbow to screw in a fitting to hook up the emergency dump hose, which then could be any size.

[peteco]

Here is my modified 4-way wye that I mentioned previously.









Pete
2006 Roadtrek 210 Popular

[dicktill]

Originally Posted by peteco

Here is my modified 4-way wye that I mentioned previously.

Pete
2006 Roadtrek 210 Popular

Hi Pete,

What are the parts/part numbers that you used and glued together?

Thanks, Dick

[peteco]

Originally Posted by dicktill

Hi Pete,

What are the parts/part numbers that you used and glued together?

Thanks, Dick

I got the wye from Amazon:

http://www.amazon.com/gp/product/B00594 ... UTF8&psc=1

The RV Sewer Hose Fitting Parts and the cap I got at the local RV store. The cylinder that is glued inside the part the cap attaches to was cut from a piece of black sewer pipe that I think I got from the RV store as well. After gluing inside the part the cap attaches to I had to cut some of the material out so it would fit onto the wye as shown below. I kept the black plastic slivers and mixed them with the plastic pipe solvent glue to make a slurry that was used when gluing the piece onto the wye as the fit was not perfect. This helped fill in any voids and hopefully made the joint watertight.

[avanti]

Am I confused? Isn't the fitting that I pointed out earlier in this thread (Valterra T1037) equivalent to what your built? I believe that it is intended for exactly the application you describe. Or, am I missing something?

[peteco]

Originally Posted by avanti

Am I confused? Isn't the fitting that I pointed out earlier in this thread (Valterra T1037) equivalent to what your built? I believe that it is intended for exactly the application you describe. Or, am I missing something?

Yes, I think they are the same.

Pete
2006 Roadtrek 210 P

[booster]

The Valterra fitting just has a 2" pipe socket for the cleanout port. Roadtrek glues in a 2" female threaded bushing and puts a plug in it. At least in the Chevies, it is in a position that you can't screw anything into the thread to hook up a dump hose as the grey tank is in the way (see my pic from an earlier post). Your emergency dump has to be on the ground or in a bucket.

I don't want to speak for Peteco, but his modification is so that a standard 3" slinky dump hose could be attached to that fitting. The big question for me is if the setup will fit within the very tight space that is there (again see the pic). Once he gets a chance to put it in, we will know if it does fit and how it works.

[avanti]

Originally Posted by booster

The Valterra fitting just has a 2" pipe socket for the cleanout port. Roadtrek glues in a 2" female threaded bushing and puts a plug in it. At least in the Chevies, it is in a position that you can't screw anything into the thread to hook up a dump hose as the grey tank is in the way (see my pic from an earlier post). Your emergency dump has to be on the ground or in a bucket.

I don't want to speak for Peteco, but his modification is so that a standard 3" slinky dump hose could be attached to that fitting. The big question for me is if the setup will fit within the very tight space that is there (again see the pic). Once he gets a chance to put it in, we will know if it does fit and how it works.

I don't see how we can be talking about the same fitting. I just went out and took some pictures:

[booster]

Again my assumption, but what you show is the hose attached to the normal discharge end of the fitting, as used in a gravity dump system. On Roadtreks that end is attached to the macerator pump. The goal is to get an emergency dump (similar hose to what you show) attached to the other side of the fitting in case the macerator fails.

[avanti]

Originally Posted by booster

Again my assumption, but what you show is the hose attached to the normal discharge end of the fitting, as used in a gravity dump system. On Roadtreks that end is attached to the macerator pump. The goal is to get an emergency dump (similar hose to what you show) attached to the other side of the fitting in case the macerator fails.

Ah. That explains it. Not familiar with Roadtrek. But, why would they possibly use the bayonet side of the fitting for the macerator? Wouldn't it make more sense to simply turn the fitting around and plumb the macerator normally into the 2" side of the fitting?

I do not intent to criticize either OP or Roadtrek. Just curious and trying to be helpful. I am working on a similar project and want to make sure I am thinking properly.

[booster]

You certainly could turn the fitting around, but at least in a Roadtrek I don't think it would fit with the big end into the tank recess. Another issue would be that the smaller end doesn't come out at the bottom of the fitting, so it wouldn't empty completely, but the way Roadtrek used the macerator, it didn't either, so break even there.

I wouldn't be surprised that Valterra or someone else will come out with a fitting that has two outlets, one for macerator, and one for gravity with a valve on it. From what I am learning as I build our setup, and all the interest that backup systems are getting, it makes sense that the parts will become available. Hopefully for new and old systems.