Plastic pipes old sizing vs new

[Mattk]

My plastic drainage pipe from my sink has broken on the outside of the wall.I bought replacement parts but they are 40mm diameter whereas my existing piping is slightly larger than this, I assume imperially sized as it is very old. Is there some sort of old to new adaptor?

Any help appreciated how i can solve this annoying problem !

[jocky]

Use 40mm compression fittings, they should cope with the difference in size.

[stuelwell]

the problem is that there are two types of waste pipe. push fit and solvent weld. push fit is slightly smaller than solvent weld. you can tell the difference as the push fit will have a rubber ring inside the fitting and the solvent weld will have nothing, because you will need a special glue (solvent weld) you can buy this from any plumbers merchant or B&Q should stock it. or as jocky says a mechanical fitting will do the job although they are slightly bigger and quite ugly if they are on show. hope this is of some help stu

[Mattk]

thanks guys.
i have bought push fit pipes and a compression fit 'u shaped' piece.these all go together as they are all 40mm but when i tried to fit the compression fit u piece to the existing larger threaded pipe it was obvious immediately that it wasnt going to work !