Is this the proper way to connecting ABS and PVC in stack?

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pistiloyd

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I am installing an upflush toilet that runs a 1" PVC discharge. This will be connected into my ABS soil stack. I wanted to check to see if this configuration is appropriate and would work? My plan is to cut the stack and use ABS cement glue to install the wye. Then use ABS to PVC Green Transition cement to connect a 1.5"x1" PVC reducer bushing. Then use PVC primer/glue to connect the 1" PVC discharge line. Does this sound right?

IMG_0954 copy.jpg IMG_3670 copy.jpg
 
Describe how you will be able to glue that abs fitting onto your stack, after you cut it.
Think about it.
I don’t see it happening.
Hopefully I am wrong.
 
Describe how you will be able to glue that abs fitting onto your stack, after you cut it.
Think about it.
I don’t see it happening.
Hopefully I am wrong.

My thoughts are to cut the stack, glue the bottom in place to the stack and use a proflex coupling to secure the top section of the wye to the stack. I assume the stack wouldn't have enough movement in it to be able to just get the new connection in there and glued into place. Would this be correct way to connect into it?

https://www.homedepot.com/p/Fernco-...-pip_alternatives-_-202522961-_-100372287-_-N
 

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You must ONLY use special transition cement made for ABS to PVC. Typ. green color.
I wouldn't mess with gluing in the stack at all.
Use the ABS fitting, glue stubs into the hubs, and use two 3" no hub couplings on the pipe connections.
 
That PVC bushing is a pressure fitting not a dwv fitting, combos can only be used horizontal to horizontal or vertical to horizontal, if you’re transitioning horizontal to vertical you need a santee.
 
Are you tying your tee wye into a horizontal drain line. If your putting a sani-flow system in they want the reducing
wye standing straight up.
 
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Yes, it is a self contained Saniflo, so no vent is needed. Not sure if that changes anything about the venting concern. The original thought would be tie it into the vertical stack. So I should be picking up the wye below for it then, correct?


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Follow up question too. I have seen folks say it is ok to have an upflush toilet discharge into the 2" horizontal waste line before it drops into the main stack. I have seen others say that is not OK. I have plumbers over the years tell me both ways when looking at my plumbing. If this would be suitable, it would save me drywall work and make the install quicker. The plumbing looks something like below. 2" waste line above, 1" discharge coming up to it, drops into the 3" line and to the stack. What are thoughts behind this?

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Because with the combo wye, the horizontal drain will not vent properly. View attachment 26121
You don’t vent a drain though, you vent a trap. After a fixture has been vented you can tie it in with a eye it combo or however. The sani-flo tank has a vent connection so he can tie the discharge in with the combo wye if he wants

**edit

Just realized this isn’t a traditional sani flo tank. I would not tie this in with a combo. Use a sanitary tee as suggested
 
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Saniflo's "instructions" say to do a wye standing straight up as TomFOhio mentioned. So the question is if it can discharge into that 2" horizontal waste line, which empties into the stack. I continually see different answers online, which makes it frustrating. I guess I can contact the city inspector and see what is code in town? I also would like to know best practice as well for my own knowledge. Their instructions are below. Thanks again for the help.

https://images.homedepot-static.com/catalog/pdfImages/9c/9c4e7ace-de52-47b7-983e-6475119724d1.pdf
 
The IPC and the UPC codes for the USA specifically state that you tie a pumped drain line int0 a horizontal pipe with a wye. that is oriented on its back with the outlet pointed UP
It also states the tie in has to be 10 pipe diameters away from any other connection to the horizontal line

ICV Diagram.jpg
 
So just to be clear about this. The below install would be acceptable as long as I’m 10” from the sink connections? Also, is it OK to use fitting/pipe for pressurized systems for a drain line? Seems like it would be OK this way but not the reversed situation.

666972C2-AD0E-4DD2-8EF2-3A45BF6593DE.jpeg
 
Just double check your manual. Not sure about the one your putting in but the regular saniflow's that
I've installed said that the drain had to be at least 3"
 
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