I'm a total novice here so this may be a stupid question.

I need to remove about a 20 foot section of 2" cast iron drain pipe to replace it with PVC. What is the best way to cut cast iron? My understanding is that sewer gases can be flamable, so I assume cutting it with a saw-zaw may create sparks that could be dangerous. Do I need to be worried about sparks?

Alternatively, I could probably remove sections of the cast iron pipe at the "fittings" (I don't know the technical term for them). How are cast iron fittings attached (threaded? welded? etc.), and it is just easier to try to remove them instead of cutting the pipe?

I'll attach the new PVC to the remaining cast iron with the rubber hubs, so I assume my cut (or removal of the fittings) does not have to be perfectly clean.

Thanks for your help.