Crane use and maintenance: lifting equipment maintenance and maintenance by hand. Before classes a day, 10 to 30 minutes late shift 55 tons of used cranes, visits to various parts of equipment, all parts are normal 55 tons crane price, according to the provisions of lubrication, pay attention to whether the mechanical operation sound is normal, to do cleaning work and shift work, equipment in order to achieve a neat appearance, the purpose of normal operation, routine maintenance records and records to be made a fixed form shift, and as a file management. Crane safety devices: To ensure safe and reliable operation of lifting cranes equipped with better safety devices, so that in case of an accident, protect the parts or alert the operator note 55 t crane, which play a security role. Each hydraulic system relief valve: Can cause abnormally high pressure loop to prevent damage to the hydraulic pumps and motors, and to prevent the overload condition.