XFB series backward centrifugal fan is one of the most successful and efficient centrifugal fans designed in china. The connecting type fan is assembled on the same rigid frame of the fan, the drive group and the motor, thus reducing the installation difficulty, shortening the site debugging and the installation time limit. The C type fan can be matched with an integral bearing seat, and the bearing is well lubricated and has a high service life. Equipped with water seat, it can work in high temperature for a long time. C type fans can manufacture non-standard speed to realize nonstandard adjustment of parameters.