downstream of cooling plate 24 is a schematically illustrated false twist unit 28 the latter may be designed and constructed in accordance with de ps 22 13 881 or u s pat no 4 339 915 subsequent to false twist unit 28 a further feed system 30 is positioned which serves to draw yarn 12 both over heater 20 and cooling plate 24 in direction of the advancing yarn downstream of feed system 30 a heating tube 34 is positioned which is constructed preferably as a curved tubular member which is surrounded by a heating jacket 32 the heating tube 34 may alternatively be constructed as a linear tube the heating jacket 32 serves to heat the tube 34 from its outside with vapor at a certain elevated temperature adapted to the spatial conditions of the false twist crimping machine the heating tube 34 and its jacket 32 are preferably arranged in an upright orientation seamlessly connected to the downstream or lower end of the heating tube 34 i e substantially sealed against air is a transport tube 42 this allows for the yarn 12 to transport the atmosphere of heating tube 34 into transport tube 42 a connecting member 38 is provided to interconnect the downstream end of the heating tube 34 to the upstream end of the transport tube 42 and at the right angled elbow in the member there is provided a yarn guide 44 which is constructed as a pin or roll which has a circumferential groove the groove serves.