Fernco's and sump pump drains?

[Treeman]

It seems that Fernco style couplings are common on PVC sump pump drain lines, both on the Fernco brand check valve and/or as a coupling to take the system apart.

Since they are only rated to 4.3 lbs. of pressure, how are they allowed on a sump pump system? If the drain line clogged, wouldn't the pump create more than 4.3 lbs.?

Another question: Is there a reason most seem to use just the plain rubber coupling and not the banded (mission) style coupling? The banded coupling seems so much more secure.

Is it overkill to use all solid/glued PVC check valves and unions?

Thank you.

 

[stealle]

I came to the forum today to find the answer to this very question. Anyone have an answer?

 

[Sponsor]

 

[Terry]

I've been using shielded couplings for those. They typically will hold 20 feet of head. That should be enough.