Extrusion system

An extrusion system comprising:

• an extruder, operable to propel extrudate through an outlet thereof, during use;
• and
• a valve, which comprises:
• an inlet, fluidically connected to the extruder outlet, so as to receive extrudate therefrom, during use;
• a main conduit extending from the inlet to a main outlet;
• a dumping conduit, extending from a junction with the main conduit to a dumping outlet;
• a flow control member, operable to move between:
• a plurality of flow controlling positions, in which extrudate is directed to the main outlet, with the flow control member providing, for each flow controlling position, a respective amount of impedance to flow along the main conduit;
• and
• a flow diverting position, in which extrudate is directed along the dumping conduit to the dumping outlet;
• at least one seal for the flow control member;
• and
• at least one port for receiving a fluid to flush the at least one seal.