Would like to tap and thread black sewer pipe for a half inch drain to run to. I have the height for down flow and drain tube would be gone from running from across floor to floor drain now Thanks T. Ores

Hi T. Ores

According to plumbing code, NO, you cannot drill/tap into cast iron as you want to do. It's not that it hasn't been done... you can definitely drill and tap cast iron, but first, do you have a washing machine drain nearby? If so,you can run the condensate line into the washing machine standpipe.

Mark