I was working in my basement trying to replace a fitting on our 4" cast iron sewer line from the toilet and drains. The pipe runs vertical down into the concrete of the basement floor. It broke off right at floor level. Every sort of repair coupling I could find at the hardware store requires a couple of inches of exposed pipe. Is there some sort of repair coupling that can be inserted into the pipe? I've seen toilet flanges that have a gasket that expands to seal against the inside of a 4" pipe when 3 adjusting screws are tightened. Is there any sort of repair coupling that works like this and can be mated to 4" plastic pipe?
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