Explanatory notes
… piping, etc., designed, as a general rule, to interlock and to be used for draining or for the … drainage pipes, of porous common pottery, fired at only a low temperature and roughly finished. (2) Other pipes, … (e.g., chimney-pots, cowls, chimney liners and flue-blocks) ( heading 69.05 ). (b) Small tubes and tubing …