Fernco flexible coupling to schedule 30 PVC??

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Old 03-11-12, 02:57 PM
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Question Fernco flexible coupling to schedule 30 PVC??

Anyone know if a Fernco 3" flexible coupling (3.46" ID) will work with 3" schedule 30 (thin wall) PVC (~3 5/16"). Wondering if that is too much gap to fasten properly. Anyone have any feedback?

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Old 03-11-12, 06:39 PM
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What coupling are you asking about? I hope you are not connecting a toilet to thin wall pvc.
Old 03-12-12, 05:41 AM
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Oh oh...

The coupling: Fernco Flexible Coupling, fernco, fernco coupling, fernco couplings, fernco fittings, Sewer Flexible Coupling, Plumbing Flexible Coupling, Drain Flexible Coupling, Waste Pipe Flexible Coupling | Fernco (1056-33)

So, to answer your question, I am trying to connect thin-wall PVC to a toilet, in an upstairs bathroom. The reason is that I am repairing a section of existing thin-wall. I certainly could go to schedule 40 for the part I can reach, but the thin wall stuff continues on down to the main floor and beyond. The flange-to-elbow connection was leaking and damaged my living room ceiling. I am accessing this area through the now-removed damaged ceiling area (from below)

That said - my problem is that I have a set section of connections to replace, fixed in place upstream and downstream. I don't know what the magic is to fit replacements in and be able to make the connection on both sides. I'm obviously not an expert, but I see the choices as:

1. Use something like a Fernco as long as doing that in Kosher in this situation (above ground, thin-wall PVC).
2. Start all the way back at the beginning of this line (the bathroom sink drain) and rebuild an entire 5-6 foot section (possibly using schedule 40, but eventually tying into schedule 30).
3. Hire a plumber.

Option 2 sounds like the correct way to go if I do this, but presents challenges regarding access to the existing pipe.
Option 3 is sounding better all the time.

Thanks again for any feedback

Last edited by Sailfan; 03-12-12 at 08:20 AM.
Old 10-22-13, 08:47 AM
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"Genova manufactures a Sch.30 3" to Sch.40 3" Bushing. Sch.30 is the same size as sewer pipe (often referred to as "thin walled").
The part number is 65330"
(the above is the response I just got from Genova - I had the same problem as you (and there are others on the net with this same problem scratching their heads and being told to use fernco couplings). Houses in the 60s and 70s apparently had this old thin wall stuff installed as sewer pipe. It's actually still made for that purpose (Lowes, Menards etc still sell it in fact) however, it's now called schedule 30. I didn't realize this, since my old yellow thin wall pipe was clearly labeled "Genova Schedule 40 Virgin PVC". I emailed Genova to find an answer. However, while waiting for the response I decided to dig and discovered 4" schedule 40 going from the septic tank almost to the house foundation. Since I didn't have to dig too deep (we're in the Ozarks...) I opened the trench from where the 4" line from the septic met the 3" thin wall stuff, and decided to rip out the thin wall, especially since all the new bathroom plumbing I'm installing is regular schedule 40. Only hard part was digging under the foundation! Rocks! Then today after all the work I got the response from Genova about the adapter sleeve. Too late now - I'm glad I'm getting rid of that old sh#t while I'm at it. (pun intended) Genova never did explain how this old thin walled pipe got labeled "schedule 40"
Old 10-22-13, 09:04 AM
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Thanks for the additional response butch...

Hmmm probably sdr 32 or sdr 35 pipe...

PVC Pipe

but anyway old thread and I am closing. Please start new thread with any other questions...

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