风管的级别划分为动压，静压，全压。
The level of duct is divided into dynamic pressure, static pressure and total pressure.
风管，是用于空气输送和分布的管道系统。有复合风管和无机风管两种。复合风管以Durkduct风管为代表。可按截面形状和材质分类。
Air duct is a pipeline system for air transportation and distribution. There are two kinds of composite duct and inorganic duct. Durkduct duct is the representative of composite duct. It can be classified by section shape and material.
风管制作不锈钢风管制作是在咬口缝、铆钉缝、法兰翻边四角等缝隙处涂上密封胶（如中性玻璃胶）。涂密封胶前应清除表面尘土和油污。
Air duct is made of stainless steel air duct. Air duct is made of stainless steel air duct. Sealant (such as neutral glass glue) is applied to the seams of bite seam, rivet seam and flange flange flange flange flange flange. Before applying sealant, dust and oil should be removed from the surface.
按截面形状，风管可分为圆形风管，矩形风管，扁圆风管等多种，其中圆形风管阻力最小但高度尺寸最大，制作复杂。所以应用以矩形风管为主。按材质，风管可分为金属风管，复合风管，高分子风管。
According to the cross-section shape, the air duct can be divided into circular air duct, rectangular air duct, flat round air duct and so on. The circular air duct has the smallest resistance but the largest height and size, and its fabrication is complicated. So rectangular duct is the main application. According to material, air duct can be divided into metal air duct, composite air duct and polymer air duct.