Carbon steel welded duct is made of carbon steel through the welding process of forming the pipe, welded pipe can be divided into two kinds of round and rectangular according to the different requirements of the user, the production of a variety of shapes, a variety of specifications and models of the duct welded duct inside and outside the wall smooth, low resistance, beautiful, airtightness is good, high compressive strength, can be suitable for very complex ventilation projects its cost is higher than the zinc-coated duct, easy to transport and adapt to the scene of the change. Welded mouth is tight, good sealing, can be over the water does not leak, to ensure that customers use no oil leakage No water leakage of the air duct, the service life of the air duct up to 10 years or more, suitable for high-pressure exhaust dust removal system and exhaust gas treatment system.