4 inch PVC to 8 inch clay

[TheInsulator]

I need to replace the old 3 1/2 inch OD cast iron soil pipe with a 110mm pvc, as always nothings straight forward.

The cast iron is sitting into some sort of clay having an outer diameter of about 8 inches. I was hoping to find a rubber boss around the existing pipe that would just pop out, but it looks to be some sort of concrete.

So how do I go about this, firstly trying to remove the existing without cracking that clay collar, and then if that works, what kind of fitting to make that 110mm to approve 6 1/2 inch ID connection tig

 

[TheInsulator]

My first thoughts were to muse one of these with the new pvc sitting in the top, and the narrower bottom half being roughly the OD of the existing cast iron, so if I could get the cast iron out with everything still intact I could lob it in, but would probably need some sort of seal to prevent stones soil etc making there way in.

 

[TheInsulator]

It looks like it could be this type of clay bell pipe, so maybe that adapter I have would sit nicely in there, and I could re-fill the collar area with cement.

 

[dilalio]

Cut the cast and then use a fernco flexible coupling.

 

[Hugh Jaleak]

Cut the Collar off the end of the Clay pipe, that'll release the Cast for removal. Then either a DC-1 as in your pic, into the cut end of the Clay, or a Flexseal over the cut end. The DC-1 would be the better option as nowhere for solids to catch and/or collect.

 

[dilalio]

Cut the Collar off the end of the Clay pipe, that'll release the Cast for removal. Then either a DC-1 as in your pic, into the cut end of the Clay, or a Flexseal over the cut end. The DC-1 would be the better option as nowhere for solids to catch and/or collect.

That's what I'd do hugh but OP may not have or be skilled with a grinder

 

[TheInsulator]

Ok may be the way to go, hoping to only do this once
But is that DC1 I have likely to fit snuggly into the clay pipe? Or is the clay diameter likely to be 6;inches after the collar?

 

[denso13]

Or is the clay diameter likely to be 6;inches after the collar?

Likely to be 4".

 

[dilalio]

Likely to be 4".

Or 3"
Macalpine do a fitting for both OP.

 

[denso13]

Or 3"
Macalpine do a fitting for both OP.

3" clay drainage? Never came across that.

 

[dilalio]

3" clay drainage? Never came across that.

Hmmmn! Yeah... I'm thinking cast more likely

 

[denso13]

Hmmmn! Yeah... I'm thinking cast more likely

The op is asking what size clay he'll be left with after cutting the collar off?

 

[dilalio]

The op is asking what size clay he'll be left with after cutting the collar off?

I know.
So I'm agreeing with you!
In that the 3" adaptor would usually be for cast.