For common rope grab devices, maintenance is mainly carried out on metal structural parts, steel ropes, chains and their connecting parts, as well as parts with direct contact with relative motion. For the electrically driven grab device, in addition to the maintenance required by the rope grab device, the motor, mechanical transmission system, hydraulic system components, pneumatic system components, brake devices, electrical system devices, and radio remote control must be used. The above systems should be maintained.

  For the metal structural parts of the grab device, it is necessary to constantly observe changes in the state of the weld. For example, whether there are fine cracks and other damage; structural deformation; warpage deformation of the plate; friction and wear of the material; cracking and rusting of the paint. Repair, calibrate, strengthen and remove rust and paint according to specific conditions. When repairing the steel structure, the old paint should be removed and cleaned and properly preheated. For example, for Q235 plate, when the plate thickness is greater than 30mm, it should be preheated to 120 °C; for 16Mn plate, when the thickness is 31-40mm, it should be preheated to 220 °C.

  For steel ropes, always apply viscous grease (DIN51513-BC) on a regular basis, and pay attention to the wear and the fracture of the surface steel rope (check at least once a week) and replace if necessary. For example, there is a break in the steel rope, or inflection, flattening, or loosening, knotting, severe corrosion, and wear; when there are 30 damage points in the length of 30 times the diameter of the steel rope, it is necessary to observe the chain frequently to see if there is any crack which may cause a break. Also observe whether the clips, shackles, wedge sleeves, and wedges connecting the steel ropes are damaged. Observe whether the connecting bolts and nuts are loose or not. If necessary, replacement should be made. When disassembling the grab, it should be supported on the bracket and then the hinge shafts are removed).