The hook is one of the main parts of the half-gantry crane. Before selecting the gantry crane hook, it should be the technical certificate of the certificate of the manufacturer, etc., before it can be put into use. Otherwise, it should be inspected to find out that the performance is qualified. use. The surface of the hook should be smooth and clean, without peeling, sharp angles, cracks, etc. Do not use cast hooks. In use, it shall be inspected, repaired and scrapped according to the relevant requirements of this regulation.
1, hook inspection
A. The lifting mechanism of the human drive axle is tested with a hook with 1.5 times rated load as the inspection load;
B. The hook of the power-driven hoist is used to check the load according to the national standard.
C. After the hook is removed from the inspection load, the opening shall not increase by more than 0.25% of the original opening without any obvious defects or changes.
D. The hook should be able to reliably support twice the inspection load without falling off;
e. For hooks with mature technology, stable quality and made of common materials, the hardness should be checked one by one; right?, each batch has the same furnace number, the same tonnage, the same heat treatment hook, other mechanical properties except hardness Spot checks are carried out according to the standard.
The hooks are made of new materials, and 100% of the mechanical properties of the material machine should be tested before the quality is stabilized. The inspection agency shall comply with the corresponding material standards.best overhead crane supplier, Qualified hooks. Inadequate marks should be made in the low stress area and a certificate of certification should be issued. The contents of the tag are as follows:
a, rated crane
b, factory or production plant name
c, inspection mark
d, production number
A. The hook material should be made of high quality low carbon structural steel or low carbon alloy steel;
B. Forging hooks generally use 20 steel specified in GB 699-65 “Quality carbon structural steel grade and general technical conditions”;
C. The hook of the board generally adopts the A3 and C3 steels specified in GB 700-79 “Technical Conditions for Ordinary Carbon Structural Steel” or the 16Mn steel specified in GB 1591-79 “Technical Conditions for Low Alloy Structural Steel”.TD75 Coal cement plant belt feeder conveyor for sale
3, hook scrapping standards
a, the opening degree is increased by 15% compared to the element size.
b. The dangerous section wears up to 10% of the original size.
d, torsional deformation more than 10 °.
e. Plastic deformation of dangerous section or hook neck.
f. When the hook bushing wears up to 50% of the original size, the bushing should be scrapped.
g. the defects on the hook shall not be welded.
h, When the plate hook mandrel wears up to 5% of the original size, the mandrel should be scrapped.