JULI® Spiral Ventilation Ducting

JULI® Spiral Ventilation Ducting

The JULI® spiral ventilation duct is frequently used in positive and negative pressure in the underground, and it can blow air from outside and exhaust air from inside.

Product Detail

Product Tags

Product Informations

JULI® spiral ventilation duct is made of manganese steel with good elasticity as the reinforced steel wire and can be used under positive pressure for air blowing as an elbow in the underground. It is made by a special welding machine in Foresight with a good appearance and excellent folding performance. During ventilation, the stress is smooth and uniform, and it can bear greater pressure without the danger of blowing. The JULI® spiral ventilation duct can also be used for negative pressure and exhausting air from a tunnel inside. The reinforced steel wire is made of cold-drawn steel, which can support high air extraction pressure to meet the needs of customers.

The fire resistance of the JULI® tunnel ventilation duct is DIN4102 B1, NFPA701, EN13501, DIN75200, and all fire resistance is accompanied by an SGS test result. When a fire is present, a high flame retardant can help to limit the hazardous and harmful gases that can injure the human body.

 Product Parameters

JULI®  Spiral Ventilation Ducting Technical Specification
Item Unit Value
Diameter mm 300-2500
Section length m 5, 10
Color - Yellow, Orange, Black
Suspension - Diameter<1800mm, single suspension ring
Diameter≥1800mm, double suspension ring
Suspenion ring spacing mm 200-600
Steel ring diameter mm 5-10
Standard pitch mm 100-300
Sealing face sleeve mm 150-250
Coupling - Zipper/Velcro/Steel ring/Eyelet
Fire resistance - DIN4102 B1/EN13501/NFPA701/DIN75200
Antistatic Ω ≤3 x 108
Packing - Pallet
The above values are averages for reference, allowing 10% tolerance. Customization is acceptable for all given values.

 Product Feature

◈ Designed for both high negative and positive pressure and elbow use.
◈ Spiral reinforced by spring steel wire/individual steel ring (end ring), seams and PVC profile welded airtight, smooth inner surface, low friction loss.
◈ All ducting and fittings are available in an oval shape.
◈ Customization is possible, with a diameter range of 400 mm to 2100 mm.
◈ Flame resistance conforms to EN13501/DIN4102 B1/NFPA701/DIN75200.
◈ Standard length, 5 m, 10 m, 15m or 20m.
◈ The antistatic feature (3x108Ω) is optional. The newly developed water-based material that is used for antistatic surface treatment is an environmentally protective material without VOC emission in processing and use, and is also healthy for workers. It makes the antistatic value stabilize at 3x106Ω.


Product Advantages

Over 15 years of experience in the production of PVC flexible air ventilation ducts and fabric, a strong scientific research team, over ten engineering and technical staff with professional college degrees, over 30 high-speed rapier looms, three composite production lines with an annual output of more than 10,000 tons of calendered membranes, and three automatic ducting welding production lines with an annual output of more than 15 million square meters of fabric, provide long-term support and services for fans' company and large projects at home and abroad.


Automatic, fabric joining, duct body welding, the welding seam is even and stable, decreasing the influence of human factors on welding stability. The welding efficiency is 2-3 times that of a traditional welding machine, and the lead time is reduced.

The suspension ring is installed through steel wire reinforcement, which greatly enhances the bearing capacity of the duct.


The PVC fabric and PVC profile are made as anti-wear strips according to different ventilation requirements.

The spiral ventilation duct is coupled with zipper, Velcro, eyelet, or steel ring. The extra fabric on which the zipper/velcro/eyelet is sewed is welded to the flexible duct body to ensure that there are no sewing needle eyes throughout the ducting, reducing air leakage. The sealing face sleeve covers the zipper or Velcro, reducing the risk of bursting.

Flexible repair methods: zipper repair band, Velcro repair band, and portable hot air gun.


Several automatic ducting welding production lines with a monthly output of 20,000 flexible ventilation tubes with assured batch order lead time.

Pallet packing will be designed according to the order quantity and the container size, trying to save transportation costs.




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