A-Frame & Crown Block System Components

1

Pin

φ40×90

101.51.10.04

35CrMo Alloy Steel

1. Cyclic shear fatigue caused by repeated lifting and folding of A-frame; 2. Abrasion between pin and bushing due to insufficient lubrication; 3. Corrosion induced by drilling fluid and marine salt spray; 4. Stress concentration caused by improper installation and forced assembly.

1. Conduct magnetic particle testing (MPT) for surface cracks every 3 months of operation; 2. Inject high-pressure, high-temperature resistant lubricating grease into the pin-bushing interface every 50 working hours; 3. Before installation, verify the fit clearance between the pin and the mounting hole (standard clearance: 0.02-0.05mm) to avoid forced assembly; 4. Regularly inspect the matching locking components (cotter pins, slotted nuts) and replace them immediately if damaged; 5. Apply anti-corrosion coating to the pin surface in marine or humid environments.

2

Pin

φ30×80

101.51.10.08

40Cr Alloy Steel

1. Wear caused by relative rotation between pin and connected structural parts; 2. Fatigue failure due to long-term cyclic load; 3. Impact damage during equipment transportation and on-site installation; 4. Oxidation and corrosion in open-air working environments.

1. Install wear-resistant bushings at the pin mounting holes to reduce direct friction; 2. Use dedicated lifting tools during transportation and installation to avoid direct impact on the pin; 3. Control the lifting and folding speed of the A-frame to reduce impact load on the pin; 4. Regularly clean the pin surface and reapply anti-rust oil every 2 months; 5. Replace the pin immediately if the surface wear depth exceeds 0.3mm or if there is any sign of bending.

1

Gin pole of crown block

Customized for crown block

-

Q355B Low Alloy High Strength Steel

1. Welding seam fatigue cracking caused by long-term cyclic load; 2. Corrosion caused by marine salt spray and humid environment; 3. Local deformation caused by impact from falling objects; 4. Stress concentration at the connection due to improper installation.

1. Conduct ultrasonic testing (UT) on welding seams every 6 months to detect internal cracks; 2. Apply anti-corrosion paint (epoxy zinc-rich primer + polyurethane topcoat) to the surface annually; 3. Install protective guards around the gin pole to prevent impact from falling objects; 4. Ensure the connection with the crown block main body is firm and even, and re-tighten the fasteners regularly; 5. Avoid overloading operation and strictly abide by the rated load of the gin pole.

2

Cross drawbar

Customized

101.51.13.00

42CrMo Alloy Steel

1. Fatigue deformation caused by long-term tensile and compressive loads; 2. Wear at the pin hole caused by vibration; 3. Corrosion induced by chemical media in the working environment; 4. Damage caused by improper disassembly and assembly with inappropriate tools.

1. Regularly measure the straightness of the drawbar, and replace it if the deformation exceeds 0.5‰ of the total length; 2. Install wear-resistant sleeves in the pin holes to reduce wear; 3. Clean the drawbar surface in time if contaminated by chemical media; 4. Use special disassembly tools to avoid damaging the connection parts; 5. Conduct load testing every 12 months to verify the load-bearing capacity.

3

Pipe

φ76×5 L=840

101.51.10.06

20# Seamless Steel Pipe

1. Corrosion caused by internal fluid (oil, water) and external environment; 2. Welding seam leakage caused by vibration; 3. Local damage caused by collision during installation; 4. Fatigue cracking at the pipe bend (if any).

1. Conduct pressure testing every 6 months to check for leakage; 2. Apply anti-corrosion treatment to the internal and external surfaces of the pipe; 3. Use pipe supports to fix the pipe and reduce vibration during operation; 4. Avoid collision during transportation and installation, and check the pipe surface for scratches and dents; 5. Replace the pipe if there is any sign of corrosion penetration or welding seam cracking.

4

Pipe

φ76×5 L=970

101.51.10.07

20# Seamless Steel Pipe

1. Same as φ76×5 L=840 pipe; 2. Stress concentration at the pipe end caused by improper connection.

1. Same as φ76×5 L=840 pipe; 2. Ensure the pipe end is properly processed (chamfering, deburring) before connection; 3. Use matching flanges or couplings to ensure uniform stress distribution at the connection.

1

Wire line stop device III

Customized for wire line system

101.51.145.00

Main Body: Q235 Steel; Locking Mechanism: 40Cr Alloy Steel

1. Wear of the locking mechanism caused by frequent operation; 2. Jamming of the moving parts caused by dust and debris; 3. Corrosion of the spring component leading to reduced elastic force; 4. Malfunction caused by improper adjustment of the limit switch.

1. Clean the device regularly to remove dust and debris from the moving parts; 2. Lubricate the locking mechanism and guide rails every 30 working hours; 3. Check the spring elastic force regularly and replace the spring if it is fatigued; 4. Calibrate the limit switch every month to ensure sensitive response; 5. Conduct functional tests before each hoisting operation to verify the locking performance.

2

Sheave set

Assembly type

-

Sheave Body: QT600-3 Ductile Iron; Shaft: 42CrMo Alloy Steel

1. Rope groove wear caused by long-term friction with the steel wire rope; 2. Bearing damage caused by lack of lubrication and dust intrusion; 3. Fatigue cracking of the sheave body caused by cyclic load; 4. Corrosion of the shaft and bearing seat.

1. Check the rope groove wear depth regularly; replace the sheave when the wear depth exceeds 10% of the steel wire rope diameter; 2. Inject lithium-based grease into the bearing every 25 working hours; 3. Install a dust cover to prevent dust and debris from entering the bearing; 4. Conduct non-destructive testing on the sheave body every 6 months; 5. Apply anti-corrosion treatment to the shaft and bearing seat surface.

3

Bearing seat

Customized for sheave set

101.51.40.01

HT250 Gray Cast Iron

1. Wear of the bearing mounting hole caused by bearing rotation; 2. Crack caused by impact load; 3. Corrosion caused by humid environment; 4. Deformation caused by uneven tightening of fasteners.

1. Ensure the bearing is properly installed and the fit clearance is within the standard range; 2. Avoid impact on the bearing seat during equipment operation and maintenance; 3. Apply anti-rust paint to the surface; 4. Use torque wrench to tighten the mounting bolts uniformly; 5. Replace the bearing seat if there is any crack or excessive wear of the mounting hole.

4

Shaft

Customized for sheave set

101.52.40.02

42CrMo Alloy Steel

1. Fatigue wear caused by long-term torque transmission; 2. Corrosion caused by lubricating oil deterioration; 3. Shoulder wear caused by bearing axial movement; 4. Bending deformation caused by improper installation.

1. Replace the lubricating oil regularly to ensure good lubrication; 2. Install thrust washers to limit bearing axial movement; 3. Check the shaft straightness regularly and correct or replace it if deformed; 4. Conduct magnetic particle testing on the shaft every 6 months to detect surface cracks; 5. Ensure the shaft is properly aligned during installation to avoid eccentric load.

5

Spacer

Customized for sheave set

101.51.40.03

45# Carbon Steel

1. Wear caused by axial pressure between bearings; 2. Corrosion caused by humid environment; 3. Deformation caused by excessive axial force; 4. Scratches caused by improper installation.

1. Select spacers of the correct thickness to ensure proper bearing preload; 2. Apply anti-rust oil to the spacer surface before installation; 3. Avoid applying excessive axial force during assembly; 4. Check the spacer for deformation and wear regularly; 5. Use clean tools during installation to avoid scratches on the spacer surface.

6

Dust ring

Customized for sheave set

101.51.20.04

NBR (Nitrile Butadiene Rubber)

1. Aging and hardening caused by long-term exposure to high temperature and oil; 2. Damage caused by friction with the rotating shaft; 3. Crack caused by chemical corrosion; 4. Deformation caused by improper installation.

1. Replace the dust ring every 6 months or when it shows signs of aging; 2. Ensure the dust ring is properly installed and fits tightly with the shaft and bearing seat; 3. Avoid contact with strong chemical media (e.g., strong acids, alkalis); 4. Check the dust ring for damage before each maintenance; 5. Store the dust ring in a cool, dry place away from direct sunlight.

7

Bearing

260×360×134

-

GCr15SiMn Bearing Steel

1. Wear caused by insufficient lubrication; 2. Overheating and damage caused by high load and high speed; 3. Corrosion caused by water or impurities entering the bearing; 4. Fatigue failure caused by long-term cyclic load.

1. Use high-quality lubricating grease that matches the working conditions (temperature, load); 2. Monitor the bearing temperature during operation; stop the machine for inspection if the temperature exceeds 80℃; 3. Ensure the sealing performance of the bearing to prevent water and impurities from entering; 4. Check the bearing for abnormal noise and vibration regularly; 5. Replace the bearing when it reaches the specified service life or shows signs of fatigue.

1

Slotted nut

M24 GB6178-86 (M24-8)

-

40Cr Alloy Steel

1. Thread wear caused by long-term vibration; 2. Slot damage caused by improper insertion and removal of cotter pins; 3. Corrosion leading to thread seizure; 4. Deformation caused by over-tightening.

1. Use torque wrench to control the tightening torque (refer to GB/T 3098.1 standard); 2. Select cotter pins of matching specifications and insert them correctly to avoid slot damage; 3. Apply anti-seize agent to the thread before installation to prevent seizure; 4. Regularly check the thread and slot status; replace the nut if there is wear or deformation; 5. Use in conjunction with spring washers to enhance anti-loosening performance.

2

Washer

24 GB93-87 (24)

-

65Mn Spring Steel

1. Deformation caused by excessive clamping force; 2. Corrosion caused by humid environment; 3. Wear caused by friction with the nut and connected parts; 4. Fatigue failure caused by long-term vibration.

1. Ensure the washer size matches the bolt specification; 2. Replace the washer if it is deformed or loses elasticity; 3. Apply anti-rust paint to the washer surface in corrosive environments; 4. Install the washer correctly (the curved side faces the nut); 5. Do not reuse washers that have been severely deformed.

3

Cotter pin

5×40 GB91-86 (5×40)

-

Q235 Carbon Steel

1. Bending fatigue caused by vibration; 2. Corrosion caused by humid environment; 3. Shear damage caused by excessive stress; 4. Damage caused by improper opening angle during installation.

1. Open the cotter pin at an angle of 60-90 degrees after installation to ensure reliable locking; 2. Replace the cotter pin every 3 months in humid or corrosive environments; 3. Avoid applying excessive force to the cotter pin during installation; 4. Do not reuse cotter pins that have been bent multiple times; 5. Check the cotter pin for cracks and corrosion regularly.

4

Bolt

M20×50 GB31.1-86 (M20×50-8.8)

-

40Cr Alloy Steel (8.8 Grade)

1. Thread wear caused by repeated assembly and disassembly; 2. Fatigue breakage caused by long-term cyclic load; 3. Corrosion caused by harsh environment; 4. Damage caused by over-tightening.

1. Strictly follow the specified tightening torque during installation; 2. Conduct magnetic particle testing on the bolt head and thread root every 6 months; 3. Apply anti-corrosion coating to the bolt surface; 4. Use thread protectors during transportation and storage to avoid thread damage; 5. Replace the bolt if the thread is slippery or there is any sign of fatigue.

5

Nut

M20 GB6178-86 (M20-8)

-

40Cr Alloy Steel

1. Thread wear caused by long-term vibration; 2. Corrosion leading to thread seizure; 3. Deformation caused by over-tightening; 4. Damage caused by improper assembly tools.

1. Use socket wrenches that match the nut size to avoid damaging the nut edges; 2. Apply anti-seize agent to the thread before installation; 3. Regularly check the nut for looseness and re-tighten if necessary; 4. Replace the nut if the thread is worn or the nut is deformed; 5. Store the nut in a dry, ventilated place to prevent corrosion.

6

Washer

20 GB93-87 (20)

-

65Mn Spring Steel

1. Same as 24 GB93-87 washer; 2. Wear caused by smaller contact area with the connected parts.

1. Same as 24 GB93-87 washer; 2. Ensure the connected parts surface is flat and clean to increase the contact area; 3. Replace the washer if the contact surface is severely worn.

7

Cotter pin

4×36 GB91-86 (4×36)

-

Q235 Carbon Steel

1. Same as 5×40 GB91-86 cotter pin; 2. Damage caused by insufficient strength for the application.

1. Same as 5×40 GB91-86 cotter pin; 2. Ensure the cotter pin strength matches the working load; do not use undersized cotter pins; 3. Check the cotter pin more frequently in high-load applications.

8

Bolt

M20×185

101.53.150.01

40Cr Alloy Steel (8.8 Grade)

1. Same as M20×50 bolt; 2. Bending deformation caused by lateral load; 3. Thread wear at the long shaft part.

1. Same as M20×50 bolt; 2. Avoid applying lateral load to the bolt shaft; use guide sleeves if necessary; 3. Protect the long shaft thread with a protective cover during installation; 4. Check the shaft straightness regularly.

9

Slotted nut

M20 GB6178-86 (M20-8)

-

40Cr Alloy Steel

1. Same as M24 slotted nut; 2. Slot damage caused by frequent cotter pin replacement.

1. Same as M24 slotted nut; 2. Minimize frequent cotter pin replacement; check and maintain the nut slot during each replacement; 3. Replace the nut if the slot is severely worn.

1

Clip

60×φ30×φ3

101.51.10.05

304 Stainless Steel

1. Wear of the clamping surface caused by long-term friction with the steel wire rope; 2. Loosening caused by vibration; 3. Corrosion caused by marine salt spray and humid environment; 4. Deformation caused by excessive clamping force.

1. Use the correct number of clips (at least 3 for steel wire ropes with diameter ≤12mm) and arrange them at equal intervals; 2. Tighten the clip bolts uniformly with a torque wrench; re-tighten after the first use; 3. Apply anti-corrosion spray to the clip surface in corrosive environments; 4. Check the clamping status regularly; replace the clip if the clamping surface is severely worn or deformed; 5. Use rubber gaskets between the clip and the steel wire rope to reduce wear.

2

O-matic

Customized

101.53.150.00

Main Body: Q235 Steel; Sealing Component: NBR Rubber

1. Wear of the internal moving parts caused by frequent operation; 2. Aging and failure of the sealing component caused by oil and high temperature; 3. Malfunction caused by dust and debris entering the internal mechanism; 4. Corrosion of the metal parts.

1. Clean the O-matic device regularly to remove dust and debris; 2. Replace the sealing component every 6 months or when it shows signs of aging; 3. Lubricate the internal moving parts with oil compatible with the sealing component; 4. Apply anti-rust paint to the metal surface; 5. Conduct functional tests regularly to ensure sensitive and reliable operation.

3

5T Manual I-beam trolley

SG-5

-

Main Body: Q235 Steel; Wheels: 45# Carbon Steel with Quenching Treatment

1. Wheel wear caused by long-term movement on the I-beam; 2. Damage to the transmission mechanism caused by lack of lubrication; 3. Corrosion caused by humid environment; 4. Deformation of the hook caused by overloading.

1. Strictly abide by the rated load (5T); prohibit overloading; 2. Lubricate the wheel bearings and transmission mechanism every 30 working hours; 3. Check the wheel wear regularly; replace the wheel if the wear depth exceeds 2mm; 4. Apply anti-rust paint to the main body and hook; 5. Inspect the hook for deformation and cracks regularly; replace the hook if it fails the inspection.

4

O-matic device

Customized

101.53.151.00

Main Body: Q235 Steel; Sealing Component: NBR Rubber

1. Same as O-matic (101.53.150.00); 2. Malfunction caused by improper adjustment of the control pressure.

1. Same as O-matic (101.53.150.00); 2. Calibrate the control pressure regularly according to the equipment manual; 3. Check the pressure gauge for accuracy and replace it if necessary.

5

Safety chain

Customized

101.53.152.00

20Mn2 Alloy Steel

1. Fatigue wear of the chain links caused by long-term load-bearing; 2. Corrosion caused by humid and corrosive environments; 3. Damage caused by impact during use; 4. Wear of the connecting shackle.

1. Conduct regular inspections of the chain links and connecting shackles; replace any damaged parts immediately; 2. Apply anti-corrosion grease to the chain surface every 2 months; 3. Avoid impact loading during use; lift and lower the load smoothly; 4. Store the safety chain in a dry, ventilated place; hang it up to avoid contact with the ground; 5. Do not use the safety chain for loads exceeding its rated capacity.