L48A1 Mast Section The main load-bearing structure of the tower crane should be scrapped if these conditions are met
1, the main bearing structure of the tower crane loses its overall stability and can not be repaired.
The main load-bearing structure of the tower crane increases the computational stress of the structure due to corrosion, when it exceeds 15 % of the original calculated stress. For those without calculation conditions, when the corrosion depth reaches 10 % of the original thickness.
3, the main load structure of the tower crane can not eliminate the impact of cracks.
(1) The assembly parts, parts, accessories and accessories shall be complete and complete.
(2) The pretightening force of the metal structure bolt or rivet connection shall conform to the specifications.
(3) The main performance of the entire machine should be able to meet the rated targets.
4, all parts of lubrication equipment should be complete, lubrication should be good.
The lifting machinery specified in the Regulations on the Safety Supervision of Special Equipment must be tested by a qualified inspection and testing institution before it can be used.
