MVHR condensate trap - how do I go from 25mm to 40mm?

[Conor]

The waste trap for my MVHR is this 25mm plastic jobbie. It is ribbed at the end rather than a mechanic thread.

 

It needs to connect to a 40mm solvent weld pipe. How do I do this?

 

I've spotted 21.5mm solvent weld waste pipe and adapters to 40mm. Just can't figure out how to get from the 25mm to 21.5mm. or is there a washing machine style flexible solution?

Edited July 16, 2022 by Conor

[ProDave]

How about https://www.amazon.co.uk/Polypipe-Connector-Pushfit-Adapter-Reducer/dp/B00V911X3C

 

I would shop around though, that seems expensive