Is there a good way to go from 22mm copper to 40mm solvent weld waste pipe, please?  The condensate pipe will be copper for the first 1.5m, with the last 1m being exterior. so I'm not so worried about temperature rating of pipe.

13 minutes ago, jpadie said:

Is there a good way to go from 22mm copper to 40mm solvent weld waste pipe, please?  The condensate pipe will be copper for the first 1.5m, with the last 1m being exterior. so I'm not so worried about temperature rating of pipe.

Hi. The condensate CANNOT be run in copper as the discharge is acidic. 
 

All components / connections / pipe etc need to be plastic / PVC. 

 

You also need to make sure the condensate doesn’t discharge into a cast iron soil stack too. 

 

Condensate is cool / cold btw, no need for any heat consideration. 👌

I'm so sorry.  I used the wrong words as I was thrown by the Screwfix catalogue 

 

This isn't condensate it's the discharge from a tundish.   Really sorry to have spent your time on my error.  

You can get a rubber bung type connector with a bore to suit 20mm plastic or 22mm copper and a ribbed exterior to fit a 40 or 50mm waste. Best to fit on a downward pipe run. Or a universal rubber sleeve reducer with jubilee clips either end.