An extrusion and conditioning apparatus, with an extruder (2) which, in a conveying position, leads into a conveyor housing (10) connected in a sealed manner to a pneumatic supply line (40) and to a pneumatic conveyor line (16), from which extruded material can be removed pneumatically, especially by means of superheated steam, via the conveyor line (16), characterised in that the extruder (2) can be moved from the conveying position into a bypass position, in which the extruder (2) leads to the exterior of the conveyor housing (19), having a means (6) for sealing the supply and conveyor lines (40, 16) and the conveyor housing (10) vis-a-vis the surroundings when the extruder (2) is in the conveying and bypass positions.
