Railway duct is a very common ventilation and exhaust pipe infrastructure, which can effectively circulate air and reduce the concentration of harmful gases. Therefore, the material of main products such as iron pipes, sheets and profiles is very strict. The following is a detailed description of the production requirements of iron pipes by  Co., Ltd.

　　1. 焊縫外觀檢查，無氣孔、沙眼、夾渣、裂紋等缺陷，糾正鋼板焊接后的變形;

　　1. Weld appearance inspection, no air hole, trachoma, slag inclusion, cracks and other defects, correct the deformation of steel plate after welding;

　　2、鐵板風道保溫層采用聚苯乙烯泡沫板生產，泡沫板密度:40納米結構/m3，厚度35納米結構(表面溫度不得低于5℃)，保溫層邊緣接縫采用梯形或榫槽結構，用樹脂糊制而成。

　　2. The insulation layer of iron plate air duct is made of polystyrene foam board. The density of the foam board is 40 nanometer structure /m3, the thickness is 35 nanometer structure (the surface temperature should not be lower than 5 degrees Celsius). The edge of the insulation layer adopts trapezoidal or tenon groove structure, and is made of resin paste.

　　3.將鐵板風管的風管、風口與帶保溫層的軟管連接;

　　3. Connect the air duct and tuyere of the iron plate air duct with the hose with insulation layer;

　　4. 鐵管的管道應平整、筆直。主風管小于或等于1.5 mm，但小于或等于1 mm;

　　4. Pipes of iron pipes should be flat and straight. The main duct is less than or equal to 1.5 mm, but less than or equal to 1 mm.

　　5. 鐵板風管及附件表面平整，電弧均勻，縱向接縫應錯開，咬合接縫應緊密，寬度應均勻;

　　5. The surface of the iron plate air duct and accessories is flat, the arc is uniform, the longitudinal joint should be staggered, the occlusion joint should be tight and the width should be uniform.

　　6. 制造鐵管及配件，外徑或外徑允許偏差小于或等于300mm為- 1mm;-2mm大于300mm。風管系統中所有直角彎頭均安裝在消聲器彎頭內，消聲器彎頭內安裝鍍鋅鐵板導向器;

　　6. Making iron pipes and fittings, the allowable deviation of outer diameter or outer diameter less than or equal to 300 mm is - 1 mm; - 2 mm is more than 300 mm. All right-angle elbows in the air duct system are installed in the muffler elbow, and galvanized iron plate guide is installed in the muffler elbow.

　　7. 鐵板風管的風管采用機械咬口，整齊嚴謹，接口內表面采用玻璃膠。

　　7. The air duct of the iron plate air duct adopts mechanical bite, neat and rigorous, and the inner surface of the interface adopts glass glue.