I need to add a drain and there is existing schedule 40 plastic pipe, can I cement abs plastic pipe to the schedule 40 using multi purpose cement?

Hi TFMDAN:

Multi. Purpose cement (1st pic.) can be used on PVC and ABS, but it can't be used to cement ABS directly to PVC... ok? The materials are just too dissimiliar...

They do make a TRANSITION CEMENT (2nd pic.) exactly for transitioning from ABS to PVC, but the people that make it (OATEY) has stated that it is not meant for use INSIDE a home... only made for underground connection and then only 1 connection... the transition from ABS to PVC. So I can't recommend it, but if you can find it and you want to use it... up to you.

In fact, the most legal way to do this in terms of plumbing codes would be to use the multi. Purpose cement to cement a PVC male adapter onto the PVC and an ABS female adapter onto the ABS and then screw the two together using some teflon tape on the male threads!

One other legal way to do it would be to use a plastic x plastic SHIELDED CLAMP (3rd pic.) These are available at all home supply stores... ;)

Anyway, hope that is all clear. Let me know if you have more questions here.

MARK