Proflex 3000-44 vs corrugated

[PVC24]

Hello, I really would like to use the corrugated metal shield 4 " to connect pvc to cast iron 4 " becaquse i can easily roll it back on the cast iron to install a 4 " backwater valve in my basement. A plumber told me to use a proflex 3000-44 smooth stainless shield coupling. I practiced in a hardware store trying to roll back the smooth stainless shield 3000-44 , and it was thicker and impossible to keep it folded back over a pipe. The thinner corrugated metal shield is much easier to work with. Am I asking for trouble using the corrugated metal coupling, or is there any tricks to connecting a backwater valve between two sections of cast iron?

Thanks

 

[Breplum]

Conventional 4" nohub couplings are not sized to accommodate different diameter pipes as cast x plastic are. Not a problem with two inch, but three and four are definitely only done with couplings made for the different diameters, and the thinner rubber on the plastic side is the part to fold back. you can cut out the bead to make sliding work if necessary.
Expensive but suitable and easy to use, the special shielded adjustable sewer repair couplings are ideal, and the center bead can be cut out.

FLEX-SEAL® ARC Shielded Adjustable Sewer Repair Couplings - Mission Rubber LLC

www.missionrubber.com

Fernco calls their version 'Strong Back' couplings. Found at plumbing supply shops.
You also need special torque driver to tighten any band properly, depending on specs of the band.
Easy to screw up by not knowing what you are doing.
Backwater device should only be installed as per code and that means: only serve that portion of the drainage below the outside overflow/manhole level. Not to be used on the entire house plumbing.

 

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[PVC24]

Thanks for your reply, i attempted to use the 4 inch no hub corrugated metal shield to connnect the pvc to cast iron because it is easy to roll back. there was at most 1/32 inch gap between the pvc and cast , and I still feel a slight leak on both sides of backwater valve. Would a thicker rubber non shielded coupeling be better to stop leaks? At this point I don't care about code>

Thanks

 

[Breplum]

The transition couplings, made for exactly the transition specified are the only coupling that will work reliably.