Struggling to find right adaptor to clay drainage

Need to connect 68mm rainwater pipe to old clay underground drainage pipe and struggling to find the right adapter. Wondered if someone could point me in the right direction. Clay pipe is socketed type (O/S diameter of socket is 6". I/S diameter of socket is 5". internal bore of pipe seems to be around 3") Inside of socket is ribbed (think its a rib rather than a thread). I can find plenty of adapters from 110mm but not to the dimensions above.

Thanks
Steve.

Any good?

http://www.wardsflex.co.uk/acatalog/Pipe-Repair-Couplings.html available from most builder merchants difference shape, sizes, reducer etc

Should really go to soakaway though but you know how it is

You may find a 68mmx110mm plastic adaptor will fit inside the clay socket without falling down the pipe! This will cover the hole and then you can make good with a stiff mortar mix. (Ensure none goes down the pipe!)

I doubt you'll get anything to take you directly from the old salt glazed pipes you have directly to 68mm downpipe, I cant see anything in the 'Flex-seal' range. Only other option is to cut the collar off the salt glazed, convert to 110mm plastic and then fit a suitable adaptor.

Thanks for the help guys.Im not on mains drainage. Its an existing drainage pipe that i think does go to a soakaway. It's not feeding into my septic tank that's for sure as no evidence of this when i put a hose down it.

Thanks

Steve.