[Tinc]

What is the proper connector or connection to use to connect ABS sewer line to Cast Iron sewer line underground? Both are 3".

 

[Alan]

3" Banded coupling is what we would use in my area. Also known as a no-hub coupling.

 

[Tinc]

Will it rust? How long will it last before leaking?

 

[Alan]

Will it rust? How long will it last before leaking?

It's a rubber coupling with a stainless shield and 2 stainless hose clamps.

 

[plumber666]

For underground, I use Fernco couplings. Similar, but thicker rubber, no stainless band, just 2 gear clamps. Just a personal preference, no-hubs are fine too.