Countercurrent stripping pipe for removing volatile organic constituents from reaction products, having a column pipe (201) composed of a plurality of pipe sections (201a-d), in which trays (202) are arranged, connections (205, 208) for supplying and removing the reaction products and connections (206, 207) for supplying and removing at least one stripping agent in countercurrent to the reaction products. In accordance with the invention, a plurality of successive trays (202) in each case are joined to one another and form at least two inserts (211a-c) which can be removed from the column pipe (201).