There are two ways to reinforce the duct. One is the corner reinforcement, one is the plane reinforcement. 250 ≦ side length ≦ 400mm when the use of angle reinforcement; duct side length> 400mm when the use of plane reinforcement.

    1,  the wind angle reinforcement is the corners of the duct at the  thickness of 0.75mm above the galvanized rectangular gasket, right angle  gasket width and duct plate thickness equal to the side length of not  less than 55mm.

   2, the plane reinforcement is to  strengthen the support on the need to strengthen the side of the duct  with a wheel cutting machine cutting, cut off the DN15 galvanized pipe. In the galvanized pipe at both ends, each into 60mm long round wood. Use a clamp to secure the round bar at both ends of the galvanized pipe. According to the design requirements with steel ruler in the air duct to determine the strengthening point. Side  length ≧ 2000mm need to increase the external reinforcement, external  reinforcement ∠30 * 3 above the angle made of steel hoop, hoop tight  duct.