3" CI to 68mm plastic rainwater?

[divetrucker]

I have an old 3" CI rainwater system with a kitchen waste connected into it.

I want to replace this part of the system and have three questions:

Is there a 3" plastic system that would be a direct replacement?

If not where can I get an adapter to let me re-do the whole lot in 68mm plastic?

I intend to reconnect the sink waste into the system but dont see any specific fittings to allow this in either 3" or 68mm. Would I have to use a 3" / 68mm tee piece and somehow seal the 40mm sink waste into the branch of the tee?

Any help appreciated.

 

[WHPES]

Firstly does you rainwater all go to the foul drain? If not, you should not be connecting kitchen wastes to it.

If it does, then I believe you can still get the adaptors between the two size RWP.

I think the smaller diameter is by Terrain or Rymway products and you will have to google it

 

[divetrucker]

Yes, it is a combined system and I am merely refurbishing part of the system.

I will try looking at those 2 companies.

 

[WHPES]

It should be marked on your existing system, usually on the joints, fittings or spigots.