Hello all,
In the process of replacing a corroded galvanized sink drain that runs into this piece of cast iron that looks like an elbow with threaded nipples for drain on each side.

Thinking of replacing it all back into the corner wall where it meets a combo tee below the vent stack with shielded fernco coupling.

The combo is black plastic (abs?), should I just use another shielded coupling and go with white pvc sch. 40?

Thanks in advance!



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That is what I would do.

Are you saying that a cast iron closet bend is connected to a plastic sanitary tee? That is very strange unless someone did a partial repipe at some time.

Thank you for that clarification, hj. Yes it was a partial replacement; the vertical portion in the wall was replaced a while ago and I guess they left the cast iron closet bend intact with the new combo.

Is there some kind of pvc closet bend that would closely match this 4" iron one with connections for 1.5" inch drains?

Thanks

They do not make "tapped closet bends" other than cast iron, and even those have been illegal for at least 70 years.

I looked a little closer and that black no hub combo is actually cast iron. I didn't think they would still be using it over plastic 13 years ago around the time of partial replacement.

Is there anything legal with inlets on it to connect to a bend. I read here that in certain jurisdictions that there are exceptions.

It is not a question of "legal", it that no one makes them. You can use conventional combos or "Y"s if you have the space for them.

It was NOT used at the time of the partial replacement. IT was already there since the building was constructed.

hj, thank you for your help so far.

With the age of this home (pre 1900), I am assuming the no hub connected combo came after the time of original plumbing.

Thus I am under the impression that the combo is not as old as that bend nor the fairly oxidized vent stack to the roof above it, which you cannot see.

All I would like to do is replace the whole bend and the two drains connected to it. As it stands the flange is not fastened to the 3/4" subfloor.

I am concerned about the issue of venting to code since there is only a vent stack at the combo. That would be considered a dry vent?

I believe there is space for two more combos before the bend up to the flange, or perhaps I could reroute the sink drain to join the tub leg, then connect to the bend.

I will post a drawing to be more specific.

Here is a rough drawing of what I have thought up. Concern is that the sink and bathrub will be wet vented, am I correct?

According to your drawing, they are NOT wet vented. In fact they are not vented at all.

What is the lowest I can rotate this wye (GREEN)? I think I understand it can't be on its side. I would have some clearance if I didn't have to roll it up 45*

If I can't roll it lower than 45* than how does this sound:

Put a sanitary T there with a side inlet in place of the existing CI sani T. Then I would have to make a few bends around the joist (RED) that ends under the wall but I'd rather not do this since I can barely squeeze a 45 street by the copper which would have to be moved in that very confined space.











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Well after removing a mixture of galvanized, copper, lead and brass drains I built a little platform to stabilize the new SS pvc flange.

I used a CP43 to go from the 4" CI sani T to a 3x3x2 street wye.

This gave me just enough room to maintain my rough in and connect up the 4x3 closet bend which I believe you had recommended, hj, in other posts. I feel Better knowing the flange has been glued inside the fitting.

Bands torqued to 60 with my in/lb automotive wrench. Pitch good at 0.25

Tried to keep the wye as close to 45* as possible.