New construction and couplings in 3" PVC drain?

Hello,

In new construction, does code allow couplings in a short run of 3" horizontal drain pipe? Saw an approximately 4' long drain pipe today that had two couplings in it. There should not be a need for that unless the pipe was damaged. I did not think couplings were allowed (especially in such short of a run.).

As long as the couplings are of the proper type and installed properly, it isn't a code issue. Now, whether it was a good idea or not to use couplings (which cost more maybe than the pipe involved) is another question.

Sometimes plumbers do things out of necessity - didn't have the right length of pipe, can't stop the job to go to the store, etc.

There are many conditions which could require "couplings in a short section of pipe", but few, if any, are "improper".