Flushing double sewer lines with wye

[Krow]

I have two sewer discharge ports - one grey only for our rear kitchen and the main black/grey midline. I have one Rhino Flex 15' line and a 10' extension.  I've been dumping the main line (B then G) then moving the connection to the kitchen line and flushing that.  Works OK when we're only a day or two at a site.  Gets to be small pain when having to do it a few times per week, especially with the slide out.

So I bought a 'Wye' adapter and am about to buy another extension to allow the two extensions to run from the two discharge ports to the wye and then the 15' from there to the sewer outlet. But now I'm wondering about the actual dump procedure with this setup.  Dumping the black will flow partway up the kitchen line I would think.  The main grey would look after some of that.  Then flushing the kitchen will no doubt force some of the first discharge back up the main line. So now I have two hoses with some 'stuff' in each with only a clear water rinse in the black tank.  With no gate valves at the wye (I know I can buy one but that's more $$ and, worse, something else to carry) how do you ensure both lines are completely flushed to ensure I don't get drowned in 'it' When in unhooking everything. Is there an easy and dry way to do this? Or am I better off to stay at what I'm doing now - single hose being transferred as needed?

 

[SeilerBird]

I would stay with the current system.

 

[lynnmor]

I use a garden hose and suitable adapters to run from the kitchen outlet to the sewer, I see no need to flush the garden hose and it does double duty as my black tank flush.  Running 3" hose and adapters is overkill for a little dish water.

 

[Rene T]

I would open the kitchen gray water tank first. Then go right to the other gray water tank and open that drain. By the time you open the second gray water drain, the stuff that would have been in your kitchen pipe would have already been flushed down. Let those 2 tanks drain till empty.

 

[Krow]

I use a garden hose and suitable adapters to run from the kitchen outlet to the sewer, I see no need to flush the garden hose and it does double duty as my black tank flush.  Running 3" hose and adapters is overkill for a little dish water.

I'm kinda new to this.. what type of adapters are available to use a garden hose?  Think I've seen one online the has a bayonet cap with a hose attachment.  But what about the sewer end?  Is there an dapter that allows you to hook it into the main system? (I use a RhinoFlex).

Thanks everbody else for their input as well.

 

[John From Detroit]

I'm kinda new to this.. what type of adapters are available to use a garden hose?  Think I've seen one online the has a bayonet cap with a hose attachment.

There is also one that attaches to the RV, in fact you described it the "CAP" with the hose adapter.

On my RV I have 3 tanks.. I would not use that method on the gray tank but I do on the wash tank. More on this in a second

Black tank dumps via a 3" pipe into the 3" hose into the hole in the ground (Sewer inlet)
Gray is "T"ed into same "outlet" on the RV so naturally same hose, but after I dump the black, so as to "Flush" the hose.  Gray water includes the kitchen sink. and food.

Wash water (Shower and rear (main) bath lavs) goes via a 3/4" gray garden hose, Via a Valterra cap. to the flush connection on the sewer elbow.. That is if I ever use that shower. I normally do not and in fact it's all storage just now.  But I have in the past and that's how I plumb it.

One thing if like the prior poster who quoted you use a garden hose both for GRAY (including kitchen sink) and the "Flush" hose. be sure to flush the hose before you connect to "The Flusher" as food particles on the hose side of the sprayer will clog it.

 

[Tom]

This is what you need:

https://www.amazon.com/Camco-Durable-Connection-Connection-39463/dp/B000BQKBP2/ref=sr_1_7?ie=UTF8&qid=1528072159&sr=8-7&keywords=rv+sewer+hose+adapter

The adapter is normally at the tank drain end, not the sewer end of the drain hose.

 

[Krow]

This is what you need:

https://www.amazon.com/Camco-Durable-Connection-Connection-39463/dp/B000BQKBP2/ref=sr_1_7?ie=UTF8&qid=1528072159&sr=8-7&keywords=rv+sewer+hose+adapter

The adapter is normally at the tank drain end, not the sewer end of the drain hose.

Thanks for that. What I'm wondering, though, is where does the other end of the garden hose go? Do you have to remove the main sewer hose from the drain to flush it there?

I guess I'm over-complicating all this.  I already bought a wye adapter but seems using it will only create issues with properly flushing both lines adequately.  It's probably just as easy to switch the sewer drain from the main to kitchen as needed.  I appreciate everyone's input.

 

[Tom]

[quote author=Krow]What I'm wondering, though, is where does the other end of the garden hose go?[/quote]
It goes into the campground sewer. One caveat ... some city/local regulations require that the entrance to the sewer be "sealed" with a doughnut or other device to prevent spillage &/or odor.

Do you have to remove the main sewer hose from the drain to flush it there?

If your RV sewer hose is connected to the campground sewer then, yes, you'd need to disconnect it.

 

[lynnmor]

I use a cap like Tom linked to and at the sewer end I connect the 3" hose and a garden hose with this: https://www.valterra.com/product/ez-coupler-90-sewer-adapter-thread-attachment-red-carded/?pcat_id=1794  You will also need a garden hose adapter like this: https://www.amazon.com/dp/B000FJYR5K/ref=asc_df_B000FJYR5K5499159/?tag=hyprod-20&creative=394997&creativeASIN=B000FJYR5K&linkCode=df0&hvadid=216531775325&hvpos=1o3&hvnetw=g&hvrand=4160704673227785576&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9006742&hvtargid=pla-350187143011

 

[Krow]

Thanks for that Tom and Lynnmor.

 

[gravesdiesel]

I have the same setup on my TT as you have, with the rear kitchen.  I also have a Rhino Flex system with the Y connection but I have used it only once on a longer stay.  You could hook it up and leave both gray tank valves open, then on your last day, close your bathroom gray valve to build up some flushing water to purge your sewer pipe after you dump your black tank.  Then, when you go to pack up, close your kitchen tank drain, disconnect its hose from the Y and have only your main hose connected.  Drain/flush your black tank and then your gray main gray tank. 

 

[Krow]

I have the same setup on my TT as you have, with the rear kitchen.  I also have a Rhino Flex system with the Y connection but I have used it only once on a longer stay.  You could hook it up and leave both gray tank valves open, then on your last day, close your bathroom gray valve to build up some flushing water to purge your sewer pipe after you dump your black tank.  Then, when you go to pack up, close your kitchen tank drain, disconnect its hose from the Y and have only your main hose connected.  Drain/flush your black tank and then your gray main gray tank.

Now!  That's an idea!  Thanks.