B&L International transparent duct rig with disc valves and flexible ductB&L International duct demonstrator beside the Strefa Instalatora pylonDamper actuator and zone valve displayed at B&L International duct rigClose view of transparent duct sections at the B&L International displayB&L International duct rig with flexible connection and hall beyondFlexible hose connections and plenum box on the B&L International rigEnd view of B&L International transparent duct demonstrator