... ventilation purpose, diameter from 80-1500mm. The spiral tubeformer is used to produce the round rigid ... Diameter of round tubes: 80mm ~ 1500mm.2. Max. tube length: unlimited.3. Thickness of strip: 0.4 ~ ... pneumatic hydraulic station: 8kgf/cm2Key words: spiral tubeformer, spiral duct forming machine, ventilationd duct machine, spiral tube former, spiral duct former. Ventilation duct spiral tube former