Scrap replacement standards for parts of single-beam cranes

Table of Contents

Although the single-girder crane used in the workshop has a long lifespan, the service life of the single-girder crane may be greatly reduced due to the different use environment and poor maintenance work . Because single-beam رافعة أجزاء are vulnerable parts, their service life is also very limited, so when each part reaches the scrap standard, the user will replace it in time to avoid damage to the parts and major accidents due to untimely replacement.

The editor of our factory introduces the replacement standards for the scrapped parts of the single-beam crane:

1. Scrap of metal structures

1.1 When the main stressed components lose their overall stability, they should not be repaired and should be scrapped
1.2 When the main load-bearing components are corroded, inspection and measurement shall be carried out. When the load-bearing capacity is reduced to 87% of the original design load-bearing capacity, if it cannot be repaired, it shall be scrapped. When the thickness is 10%, it should be scrapped if it cannot be repaired.
1.3 When cracks occur in the main stressed components, measures should be taken to prevent the cracks from continuing to expand according to the stress and crack conditions, and measures to strengthen or change the distribution of stress or stop use.
1.4 When the main force-bearing components cannot operate normally and safely due to plastic deformation, they shall be scrapped if they cannot be repaired. For general bridge type cranes, when the trolley is in the middle of the span and the deflection value of the main girder in the middle of the span reaches 1700 below the horizontal line under the rated load, it shall be scrapped if it cannot be repaired.

2. The scrapping of the hook

2.1 The hook should be scrapped when one of the following situations occurs
- a. Cracks
- b. Dangerous section wear reaches 10% of the original size
- c. The opening degree is increased by 15% compared to the original size
- d. Torsion deformation exceeds 10
- e. Plastic deformation of dangerous section or neck of hook
- f. When the plate hook bushing wears up to 50% of the original size, the bushing should be scrapped
- g. The mandrel should be scrapped when the wear of the plate hook mandrel reaches 5% of the original size
2.2 Defects on the hook shall not be repaired by welding

3. Scrap of the reel

The reel should be scrapped when one of the following situations occurs

a. Cracks
b. The cylinder wall wears up to 20% of the original wall thickness

4. Retirement of welded chain for lifting

The welded circular chain should be scrapped when one of the following situations occurs

a. Cracks
b. The chain undergoes plastic deformation and elongation reaches 5% of the original length
c. The diameter of the chain ring wears up to 10% of the original diameter

5. Scrap of the pulley

Metal cast pulleys should be scrapped when one of the following conditions occurs

a. Splitting
b. Uneven wear of wheel grooves up to 3mm
c. The wall thickness of the wheel groove wears up to 20% of the original wall thickness
d. The diameter of the bottom of the wheel groove is reduced by 50% of the diameter of the wire rope due to wear
e. Other defects that damage the wire rope

6. Scrap of the brake

The brake parts should be scrapped when one of the following situations occurs

a. Splitting
b. The thickness of the friction pad of the brake belt wears up to 50% of the original thickness
c. Plastic deformation of the spring
d. The diameter of the small shaft or shaft hole wears up to 5% of the original diameter

7. Scrap of the brake wheel

The brake wheel should be scrapped when one of the following situations occurs

a. Cracks
b. The thickness of the rim of the brake wheel of the lifting and luffing mechanism wears up to 40% of the original thickness
c. The thickness of the rim of the brake wheel of other institutions wears up to 50% of the original thickness
d. When the unevenness of the wheel surface reaches 1.5mm, if it can be repaired, the thickness of the rim after repairing should meet the requirements of bc in this article.

8. Scrap of wheels

Wheels working on rails should be scrapped when one of the following situations occurs

a. Cracks
b. The thickness of the rim wears 50% of the original thickness
c. The bending deformation of the rim thickness reaches 20% of the original thickness
d. Tread thickness wear reaches 15% of the original thickness
e. When the running speed is lower than 50m/min, the ellipticity reaches 1mm; when the running speed is higher than 50m/min, the ovality reaches 0.5mm

9. Scrap of transmission gear

The transmission gear should be scrapped when one of the following conditions occurs

a. Cracks
b. Broken tooth
c. When the tooth surface pitting damage reaches 30% of the meshing surface and the depth reaches 10% of the original tooth thickness
d. When the wear of the tooth thickness reaches the value listed in Table 13

When the wear of the tooth thickness reaches the value

e. When the hoisting mechanism and luffing mechanism for lifting hot metal or flammable, explosive and other dangerous goods, the wear limit of the transmission gear reaches 50% of the value in the cd item in this article

10. Scrap of gear coupling

The gear coupling should be scrapped when one of the following conditions occurs

a. Cracks
b. Broken tooth
c. When the wear of the tooth thickness reaches the value listed in Table 14

When the wear of the tooth thickness reaches the value listed in Table 14

Parts that meet the scrap standard cannot be used anymore. If you continue to use them in violation of the regulations, you may lose more than you gain. In order to reduce the frequency of component replacement, the user should do a good job of maintenance during daily use to extend the service life of the components.