The invention provides devices that are attached to an extruder making the operation thereof more efficient and convenient and allowing for a quick change over of parts used to make various products prepared in the extrusion process. A high pressure relief assembly is attached to the extruder that allows for the rapid release of pressure from the extruder at the end of the process by venting product under pressure from the extruder and the extruder also has attached thereto a quick assembly locking device that allows for the exchange of assemblies, such as a density control assembly and other assembles, without the removal of nuts, bolts, and clamps by attaching the assembly to an arm that can be moved in and out of place in front of the extruder and wherein the device has a locking mechanism that seals and releases the assembly from the extruder.
