Plastic pipe dimensions/uses question

[DonkeyApple]

There is a section of grey plastic pipe that is acting as a vent from a downstairs lavatory.

I'd like to extend it but before heading to the shops was wondering what the pipe is actually 'called'.

It's similar to guttering down pipe but a larger bore, around 80mm internal opposed to 68mm.

Thanks.

[wolfracesonic]

Probably 82mm soil and vent pipe. Not as common as 68mm rwp or 110svp so may be harder to source. Comes in push fit and solvent weld flavours. It’s also sometimes used as a larger capacity rain water pipe.

[DonkeyApple]

Thanks. Using a sleeve and solvent will keep the profile slim as required. Just needed to know the correct terminology to begin the hunt.