Need. According to Article 58 of the Fire Protection Law of People's Republic of China (PRC), it is illegal for the flue in Suzhou High-tech Zone not to be filed, so the flue in Suzhou High-tech Zone should be filed. Flue is a tubular device for discharging waste gas and smoke. Residential flue refers to a vertical pipe product used to remove kitchen fume or toilet exhaust gas, also known as exhaust duct, ventilation duct and residential exhaust duct.