x-series is a quickly assembled series for round ventilation ducts. the series except the ducts is based on
a double-lipped,factory-installed seal made from EPDM rubber. the moulding,which can withstand rough handing,
and is almost insensitive to temperature changes, has a great gas tighteness.

advantage of x-series
1. quick assembly
2. factory fitted seal with no loose fittings 
3. can be twisted and adjusted, but has no effect on the gas tighteness
4. installation without sealant or solvents
5. can be used in all kinds of climates
6. the gas tighteness can keep good from 5000 Pa negtive pressure to 3000 Pa positive pressure
7. both ends of the fittings are disposed with the process of turnup, which makes both ends smooth, reinforced
and also underformed.

statement:
1. that is impossible that the x-series can keep the perfect and complete gas tighteness. in general, the 
connection between ducts and fittings will exist the situation of air leak normally, but we can guarantee
that the leakage is much lower than the international standard. and leakage will increase with the 
increase of the differnce between inside pressure and outside pressure.
2. X-series includes ducts , bends, reducers,connection branch,couplings, joints,dampers,silences,and so on.
the detailed thicknesses and specifications can be produced as required. 
3. all the products in X-series are made of galvanized or stainless steel

Ningbo East Ventilation Engineering Co., Ltd(Yuyao Dongfang Ventilation Engineering Co.,Ltd) is an enterprise 
professionally dedicated to the design and whole-set installation of ventilation projects and production of 
metal components, a professional manufacturer of spiral ventilation pipes and spare parts and a directing unit 
formulating industrial standards, owns the most excellent and perfect manufacture process in the ventilation 
industry both at home and abroad. 
the company owns whole set of the most international advanced metal spiral ventilation pipe and spare part 
production lines provided by Swiss SPIRO Company, including JRX automatic pipe making & moulding machines, R1530 
plasma cutting machines, CU-30(line and curve) sewing stitch welding machines, COMBI triangle section locking 
machines,Lide locking machines, NC spinning machines and so on, in addition, the company introduces Japanese 
AMD NC punching machines, as well as metal plate NC producing equipment.
in outstanding physical environment, the company also accelerates the upgrading of invisible environment,
establishes perfect quality assurance system in accordance with the standard of ISO9001 International Quality 
System and was successfully awarded the title of Ningbo Famous Trademark in 2009.
the products of the company are widely used in all ventilation fields of ventilation, air conditioning, 
cleaning, dust extraction and material conveyance. the company provides large projects such as airports, gyms, 
exhibition centers, supermarkets and textile factories with all-around top-quality service