通风管道在安装时需要注意那些事项？   （1）当风管与风机连接时，应在进出风口处加软接头，其软接头的断面尺寸应与风机进出风口一致。软管接头一般可采用帆布、人造革等材料，软管长度不宜小于200，松紧度应适宜，柔性软管可缓冲风机的振动。  （2）当风道与除尘设备、加热设备等连接前，应待设备安装完毕后，按实际测绘的图纸进行预制和安装。 （3）风道安装时，进、出风日宜在风道预制时开出洞口，如需在安装完毕的风道上现开风口，其接口处应严密。 （4）当输送含凝结水或含湿量较大的气体时，其水平管道宜设有坡度，并在低点处接排水管。安装时风道底部不宜出现纵向接缝，对底部有接缝处应进行密封处理。  （5）对输送易燃、易爆气体的钢板风道，在风道连接法兰处应安装跨接线，并与静电接地网连接。

What should I pay attention to when installing the ventilation pipe? (1) when the air duct is connected with the fan, a soft joint shall be added to the air inlet and outlet, and the size of the joint of the soft joint shall be the same as that of the fan inlet and outlet. Hose joint can generally use canvas, artificial leather and other materials, hose length shall not be less than 200, tightness should be appropriate, flexible hose can cushion the vibration of the fan. (2) when the air duct is connected with the dust removal equipment and heating equipment, the equipment shall be prefabricated and installed according to the actual drawing drawings after the equipment is installed. (3) air duct installation, into and out of the open hole in the air duct should be prefabricated, if installed in the air duct on the open air, the interface should be tight. (4) when the water containing condensate or humid gas is transported, the horizontal pipe should be equipped with a slope, and the drain pipe can be connected at the low point. When installing, the longitudinal joint is not suitable for the bottom of the air duct, and the joints at the bottom should be sealed. (5) the steel plate air duct for transporting inflammable and explosive gas shall be installed with the cross connecting line at the connecting flange of the air duct and connected with the electrostatic grounding net.