1. Selection of sling specification and type when selecting sling specification, the size, weight, shape of the load to be lifted, and the service mode coefficient jointly affected by the lifting method to be used must be included in the calculation consideration, and the requirements of the given ultimate working force, as well as the working environment and the type of load must be considered. Slings and riggings with sufficient capacity and appropriate length to meet the use mode must be selected. If multiple slings and riggings are used to lift the load at the same time, the same type of slings and riggings must be selected; the raw materials of flat slings and riggings cannot be affected by the environment or load. Whether accessories or soft lifting lugs are needed or not, it is necessary to carefully consider the matching of the end of the sling with the auxiliary accessories and lifting equipment.
2. Limit angle of sling when using flat sling with soft lifting lug, the minimum length of lifting lug shall not be less than 3.5 times the maximum thickness of the hook in contact with the lifting lug, and the included angle of lifting lug movement shall not be more than 20 °. When connecting slings and lifting appliances with soft lifting lugs, the contact part between slings and lifting appliances must be continuous, unless the axial width of slings does not exceed 75mm, and the bending radius of lifting accessories must be at least 0.75 times of the axial width of slings. For example, the radius of the sling on the cargo hook is at least 0.75 times of the axial width of the sling. The width of the fabric may be affected by the curvature of the cargo hook due to the influence of part of the radius inside the cargo hook, which hinders the balance of the strength in the width range of the fabric. The sling shall not be overloaded, and the correct way factor must be used. Some ways of limiting the working force may have been given on the label. The multiple combined sling shall not exceed the maximum angle with the vertical direction.
3. Follow the good lifting experience and plan the lifting and light operation plan before lifting.
4. When hoisting, the correct use of sling connection method When the sling is correctly placed and connected to the load in a safe way, the sling must be placed on the load so that the load can balance the width of the sling; never knot or twist the suture part of the sling, never place it on the hook or lifting equipment, and always place it on the upright part of the sling, to prevent the damage of the label by keeping away from the load, hook and locking angle.
5. Precautions for the use of multiple combined slings the evaluation of the ultimate working force of multiple combined slings depends on the symmetry of the load borne by the combined slings, that is to say, when lifting, the branches of the slings are symmetrical and evenly distributed according to the design, with the same vertical angle. 3. For the combined sling, if the branch cannot bear the maximum force on one branch according to the design uniform force, it will be the sum of the maximum force on the branch near the design angle. The same result will be calculated in the 4 combined sling if it is not a rigid load. Note: for the rigid load, most of the gravity may be supported by three or even two of them. The remaining one only protects the balance of the load. 6. The protection of rigging during hoisting The sling shall be away from sharp edge, friction and wear. Whether it is away from load or lifting appliance, the appropriate part of the sling shall be strengthened and protected from damage by sharp edge and wear. It is necessary to strengthen the protection supplement if necessary.
6. To ensure the load balance during lifting, the sling must be used in a safe way, and the load cannot be tilted or slipped from the sling; the sling must be arranged above the center of gravity of the load and the lifting point to make the load balanced and stable. If the center of gravity of the load is not below the lifting point, the moving sling may cross the lifting point. Cause danger.
7. If the basket crane is used, the load safety can be guaranteed, because there is no locking behavior like the lock crane, and the sling can be turned through the lifting point. It is recommended to use two slings together. The sling body suspension shall be as vertical as possible, which is conducive to ensuring the equal sharing of load between branches. When the flat sling is locked and hoisted, it should be allowed to place the natural angle (120 °), so as to avoid heat generated by friction. The sling is not subject to the forced position, nor attempts to make a tight grip. The correct safety way is to use a double locked sling. Double locking crane ensures safety and prevents the load from falling from the sling.
8. In the process of hoisting, pay close attention to ensure the safety of personnel, and warn the personnel in the dangerous state. If necessary, withdraw from the dangerous area immediately. Keep hands or other parts of the body away from slings to prevent injury when slings are loose.
9. In the process of hoisting, it is necessary to adopt the model hoisting method. The sling is lifted loosely until the sling is tensioned. The load is gradually lifted to the predetermined position, especially when the basket crane or free tension is applied, the friction force bears the load.
10. Control the rotation of the load. If the load tends to tilt, the lifting object must be lowered to ensure that the load is constrained and prevent the unexpected rotation of the load.
