What shockproof measures should reducer have?

　　The roundness of reducer shall not be greater than 1% of the corresponding end diameter, and it is allowed to float up and down for 3mm. For example, 300 Series Stainless Steel Eccentric Reducer is smaller than that of the small end section. For the dip pipe of reducer, it is also pointed out that the ultimate torque at one end cannot be completely transmitted to the other end. On the other hand, the concept of torque is gradually transformed into bending moment in the process of transmission. The bending moment of one end face of a 90 degree bend can be converted from that of the other end face. A finite element modeling method for concentric, eccentric and reducer pipes is proposed. In the process of reducing or expanding deformation and pressing, the method of cold pressing or hot pressing can be determined according to the unsuitable environment of material and changing diameter. In general environment, cold pressing method should be used as far as possible, but hot pressing method must be used in case of work hardening and thick wall caused by multi diameter change.