Size: Diameter is from 21.5 in to 406.4 mm, the thickness is from 0.6mm to 20mm ,  the length is from 1m to 12m ;
Standard : GB/T3091-2001 , BS 1387-1985 , DIN EN10025 , EN10219 , JIS G3444:2004 , ASTM A53 SCH40/80/STD , BS- EN10255-2004 

Galvanized pipe includes galvanized round pipe and galvanized square pipe.
Galvanised steel pipe include hot-dip galvanised and electric galvanised ,
Galvanised steel pipe connection: thread, welding.
Galvanised square pipes are widely used in steel structures.
We are the manufacturer in China that supply the world.

Advantages of galvanized spiral duct
High strength, low resistance, good sealing performance, beautiful appearance, simple installation and long service life.
The inner and outer walls are smooth, the air duct resistance is small, and no secondary noise is produced during air supply and exhaust, which reduces energy consumption and saves operating costs;
It can be made on site, cut, drilled, and opened, and is easy to install, saving labor and time, and shortening the construction period;
Galvanized spiral air duct does not require maintenance after installation, reducing maintenance costs;

Size: Diameter is from 21.5 in to 406.4 mm, the thickness is from 0.6mm to 20mm ,  the length is from 1m to 12m ;
Standard : GB/T3091-2001 , BS 1387-1985 , DIN EN10025 , EN10219 , JIS G3444:2004 , ASTM A53 SCH40/80/STD , BS- EN10255-2004 

Size: Diameter is from 21.5 in to 406.4 mm, the thickness is from 0.6mm to 20mm ,  the length is from 1m to 12m ;
Standard : GB/T3091-2001 , BS 1387-1985 , DIN EN10025 , EN10219 , JIS G3444:2004 , ASTM A53 SCH40/80/STD , BS- EN10255-2004 

Size: Diameter is from 21.5 in to 406.4 mm, the thickness is from 0.6mm to 20mm ,  the length is from 1m to 12m ;
Standard : GB/T3091-2001 , BS 1387-1985 , DIN EN10025 , EN10219 , JIS G3444:2004 , ASTM A53 SCH40/80/STD , BS- EN10255-2004