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In HG/T 21574-2018, \"Code for Design and Selection of Lugs for Chemical Equipment\", the dynamic load factor is set at 1.2, and the unbalance factor is set at 1.125. This is a reduction compared to the previous version, where the combined impact factor due to dynamic loads and the unevenness resulting from the use of multiple lugs was 1.65. So how should these two coefficients be understood? Let’s take a look at the relevant literature: Lü Zhixian. Discussion on the Selection of Load Coefficients in Lifting Operations. Petrochemical Construction, 2016, 38(6). The relevant points are summarized as follows: In the design of lifting operations, in order to account for the dynamic loads resulting from changes in the movement speed of the object being lifted, as well as the uneven loads that arise due to asynchronous operation when multiple components (multiple slings, multiple cranes) are used to lift one object, dynamic load coefficients and imbalance coefficients are introduced in the load calculations. Dynamic load factor: The dynamic load factor is primarily related to the lifting speed of the load when lifting vertically, the elevation angle of the load (which is highest at 60 degrees), and the operating environment (land or sea, with the sea condition resulting in a higher value). According to literature, when the crane’s lifting speed is below 5 m/s, the dynamic load factor should be set between 1.05 and 1.15; whereas when the lifting speed is between 5 m/s and 10 m/s, it should be set between 1.2 and 1.3. The imbalance coefficient needs to be taken into account in situations where the center of gravity of the lifted load is offset from the calculated center of gravity, resulting in uneven loads, as well as when multiple lifting points or multiple cranes are used together and synchronization issues lead to uneven loads. When the actual center of gravity of the lifted load deviates from the center of gravity calculated in the design, or when the center of gravity of the load deviates from its centroid, an unbalanced force is generated, resulting in an unbalance coefficient; relevant standards recommend a coefficient of 1.05 to 1.25. Coefficient selection: For lifting with a single crane or for lifting general equipment, the load coefficient should be the larger of the dynamic load coefficient and the uneven load coefficient. When using two cranes for lifting, the load factor should be set as the product of the dynamic load factor and the uneven load factor. For the lifting of heavy equipment with four or more lifting points, when the lifted object tilts during lifting or the positioning of the lifting points is offset from the center of gravity of the object, the load factor should be the product of the dynamic load factor and the uneven load factor.