Plumbing Code Question

[sethpilk]

I recently experienced a sewer line break at my home that was built in 2007. The break occurred in the front yard where the sdr and abs lines connect. The plumber that repaired the line said that the coupling that was used to connect the sdr and abs pipes was a cheap coupling, so it slipped. The original contractor ran the cleanout underneath my front porch stairs, so I had to replace concrete and it ended up costing me $9,200 to get everything repaired and I'm being told that insurance won't cover the repair. My question is, was the coupling that was used to connect the sdr and abs lines within code? The plumber that repaired the break said he didn't understand how the original contractor ever passed the city's inspection when the home was built. I've attached images of the coupling that failed. Thank you for your help!

[Bill Kibbel]

Approved flex couplings used underground meet a specific ASTM standard to withstand earth loads/shear.  The only one I'm familiar with is shielded (a stainless steel  band) and has molded-in bushings.

[Marc]

2 hours ago, Bill Kibbel said:

Approved flex couplings used underground meet a specific ASTM standard to withstand earth loads/shear.  The only one I'm familiar with is shielded (a stainless steel  band) and has molded-in bushings.

Fernco?

[Bill Kibbel]

Yes, it's a coupling manufactured by Fernco.  I think it's called "Strongback".

[Les]

we typically see the stainless banded ones in direct burial.  We call them ferncos regardless.

 

[Jim Katen]

The only ASTM standard that I'm aware of is "ASTM C1173 Standard Specification for Flexible Transition Couplings for Underground Piping Systems"

That standard recognizes couplings with and without the stainless steel shear rings. I'm not aware of any code or standard that requires the rings. Certainly, in Oregon, the coupling in the original post photo would be considered correct for underground work. 

If a coupling like that fails underground it's because the pipes weren't properly supported in the trench. (Somebody over-excavated his trench and tried to support the pipe with fill.) To me this is a clear-cut installation error, not a product failure.

[Ramona R. Stults]

Endorsed flex couplings utilized underground satisfy a particular ASTM guideline to withstand earth loads/shear. The just one I know about is protected (a tempered steel band) and has formed in bushings.