An extrusion and conditioning apparatus, with an extruder in a conveying position, leads into a conveyor housing connected in a sealed manner to a pneumatic supply line and to a pneumatic conveyor line in which extruded material can be removed pneumatically, by means of superheated steam, via the conveyor line. The extruder can be moved from the conveying position into a bypass position, in which the extruder leads to the exterior of the conveyor housing, having a means for sealing the supply and conveyor lines and the conveyor housing from the surroundings when the extruder is in the conveying and bypass positions.