The transmission of dust explosions through pipes and ducts of pneumatic conveying equipment and dedusting systems can cause violent secondary dust explosions in interconnected plant units.In the following the preconditions and the consequences of explosion propagation via pipes and ducts are shown as well as the influence of dust specific explosion characteristics,dust concentration,pressure-time history at the ignition location (primary explosion),pipe diameter and process flow on the resulting flame speed and explosion pressure in the pipe.Finally,the possibilities of explosion isolation by design measures according the state of the art are described to prevent a dust explosion from spreading to others via pipes and ducts.