Build material loading

Apparatus comprising a controller to control a processing station of an additive manufacturing system, the controller operating the processing station to reduce fluid pressure in a flow pathway of the processing station, wherein the flow pathway is connectable to a build unit of an additive manufacturing system;

• and the controller, while pressure in the flow pathway is at a reduced level, operating the processing station to connect the flow pathway with a build material reservoir of the processing station to provide fluid communication between the flow pathway and the build material reservoir.

A non-transitory computer-readable storage medium comprising computer executable instructions which, when executed by a processor, cause a processing station of an additive manufacturing system to perform a method, the method comprising:

• operating the processing station to reduce the pressure in a flow pathway of the processing station, wherein the flow pathway is connectable to a build unit of an additive manufacturing system;
• and
• while pressure in the flow pathway is at a reduced level, operating the processing station to connect the flow pathway with a build material reservoir of the processing station to provide fluid communication with the build material reservoir.