The spiral duct forming machine is used to produce the round rigid air duct ... purpose, diameter from 100-1600mm. The spiral duct forming machine ZHTF-1500II is used to produce the round rigid air ... spiral duct forming machine, ventilationd duct machine, spiral tube former, spiral duct former, ventilationd duct machine, HVAC duct machine, air duct machine. High config spiral tube former machine