The role of straightening machine in used welded pipe equipment
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- Release time:2022-08-12 11:30
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【概要描述】Straightening machine is one of the indispensable finishing equipment for the production line of used welded pipe equipment to produce fluid pipe, structural pipe and thick-walled welded pipe.
The role of straightening machine in used welded pipe equipment
【概要描述】Straightening machine is one of the indispensable finishing equipment for the production line of used welded pipe equipment to produce fluid pipe, structural pipe and thick-walled welded pipe.
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- Source:
- Release time:2022-08-12 11:30
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Straightening machine is one of the indispensable finishing equipment for the production line of used welded pipe equipment to produce fluid pipe, structural pipe and thick-walled welded pipe. Although the welded pipes are straightened by random straightening rollers, there are still many less than 2%. The straightness requirements are required, which requires the straightening of these welded pipes with the aid of a straightening machine to meet the straightness requirements.
In addition, in the continuous production process of welded pipes, affected by the thickness, width, hardness and other factors of the tube blank, as well as the sudden change of the coolant, the invisible damage of the bearings in the operating parts of the welded pipe unit, etc., it is bound to destroy the balance and maintain the straightness of the welded pipe before this. The straightness of the welded pipe changes more or less due to the force of the degree of force. If the cause is found from the unit and various parts, the production process will be cumbersome, so it needs to be straightened.
For some welded pipes that have undergone weld annealing and full-tube heat treatment, the straightness is difficult to meet the requirements and must be straightened with the aid of a straightening machine.
There are also some pipes of the welded pipe unit, although the dimensional tolerance and straightness are up to the standard, but the ovality is very poor. According to the straightening principle, the pass of the straightening roller can also play a certain role in correcting the deviation of the welded pipe with large ovality in the process of straightening the welded pipe.
The straightened pipe is beneficial to the smooth progress of subsequent chamfering, hydraulic testing and packaging marking.
Straightening principle
The basic theory of welded pipe straightening of used welded pipe equipment is that in order to achieve a certain accuracy requirement after straightening the welded pipe in the bent state, it is necessary to produce a corresponding reverse elastic-plastic deformation of the welded pipe. When the welded pipe is straightened by the upper and lower pairs of inclined rollers, it rotates circumferentially and moves longitudinally at the same time. During this process, it has to undergo two deformations:
(1) The pipe between a pair of straightening rollers is bent. The limit length of the section is the length of the roll body, and the welded pipe undergoes multiple elastic-plastic repeated bending in the straightening roll, so that the original bending degree of the welded pipe is improved and the straightness is achieved in the longitudinal direction.
(2) Under the action of the straightening roller hole profile, the ovality of the cross section of the welded pipe is partially improved.
Use of straightening tubes
In order to ensure the straightness and ovality of the straightened welded pipe, the straightening sample pipe must meet the requirements of four aspects:
(1) The outer diameter error of the straightening sample tube should be less than ±0.05mm, and the ovality should be less than ±0.03mm.
(2) The straightness of the straightening sample tube is better, and the bending degree is not more than 1‰.
(3) The straightening sample tube should be made of materials with good rigidity, high strength and not easy to deform; the sample tube should not be placed flat, and it is not allowed to be placed obliquely, because the long-term oblique placement of the slender shaft sample tube will affect the straightness.
(4) The length of the sample tube for straightening should not be shorter than the length of the center line of the three straightening rollers. Generally, the length of the sample tube for φ76 straightening machine should be greater than 1.5m, and the length of the sample tube for φ114 straightening machine should be greater than 2.5m.
Adjustment amount of straightening roller
When the passing space of the straightening roller is adjusted, it is generally not suitable to change it easily. The adjustment amount required for straightening is realized by the upward movement or downward pressure of the intermediate roller, but the adjustment amount should be controlled within 4~6mm, otherwise the tube surface will be easily damaged. The straightening roller presses out the spiral marks, which affects the appearance and outer surface quality of the welded pipe.
The adjustment rule of the straightening roller is: the adjustment amount of the welded pipe with high hardness, large diameter, thick wall and serious bending should be larger; otherwise, the adjustment amount should be smaller.
Straightening speed
Thick pipes, large pipes and pipes that are not too curved can be straightened faster; thin-walled, small pipes, and pipes with large curvature must be straightened slowly, because the speed is too fast. Under the action of centrifugal force, it will bend more and more, and even bend the tube that is not very bendable. During the actual operation, if the tail flick is found to be serious, the straightening speed must be reduced immediately or the straightening must be suspended.
Usually, a detachable "n" type protective cover is specially designed and installed on the conveyor rollers 3~4m before and after the leveler to safely control the swinging range of the pipe head and tail.
The above is the working principle and use method of the straightening machine in the used welded pipe equipment, I hope it can be of some help to you. Our company has many brands and wide resources, there is always one suitable for you. You only need to inform us of your pipe manufacturing needs, and our company will provide you with second-hand welded pipe equipment that really suits your needs. Welcome new and old customers to come to consult and order.
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Time of issue : 2025-07-11
Assessing the condition of a used slitting line requires a systematic approach to determine its operational capability and remaining service life. Unlike new equipment, pre-owned machines exhibit varying degrees of wear that directly impact performance and value. Below are essential factors to consider when evaluating a used slitting line.
Structural Integrity and Frame Condition
The machine's frame serves as the foundation for precision operations. Inspect for signs of structural fatigue, including cracks, welds, or deformations in the main frame. Check for corrosion, particularly in environments where the used slitting line may have been exposed to moisture or chemicals. A laser alignment test can reveal whether critical components remain properly positioned after years of operation.
Mechanical Wear of Core Components
Examine high-wear components such as shafts, bearings, and gears for excessive play or scoring. The decoiler and recoiler mandrels should be evaluated for straightness and grip strength. On the slitting unit, inspect spindle runout and blade holder conditions. These elements directly affect the machine's ability to maintain tolerances during operation.
Electrical System and Control Reliability
Assess the condition of motors, drives, and control systems. Older used slitting lines may have obsolete electrical components that require upgrading. Test the responsiveness of the PLC or CNC interface and check for consistency in tension control systems. Modernization potential should be considered when evaluating long-term viability.
Hydraulic and Pneumatic Performance
Hydraulic systems in a used slitting line often show signs of leakage or pressure loss. Inspect cylinders, valves, and pumps for proper operation. Pneumatic components should be checked for air leaks and actuator responsiveness. Fluid analysis can reveal contamination levels in hydraulic systems.
Blade Condition and Cutting Accuracy
The slitting knives and associated tooling represent critical wear components. Measure blade sharpness and check for chips or uneven wear patterns. Evaluate the blade adjustment mechanisms for smooth operation and precision. Test cuts on sample material reveal the machine's current cutting capability.
Material Handling System Functionality
Assess the condition of levelers, straighteners, and feed systems. Look for worn rollers, misaligned guides, and tension measurement accuracy. The material handling system significantly impacts the final product quality and operational efficiency of the used slitting line.
Documentation and Service History Review
Request maintenance records and operational logs to understand the machine's service background. Regular servicing and proper lubrication history indicate better-preserved conditions. Verify hours of operation and review any major repairs or component replacements.
Performance Testing Under Load
Conduct trial runs with actual production materials to evaluate the used slitting line under working conditions. Monitor vibration levels, noise patterns, and temperature variations during operation. Measure slit material for dimensional accuracy and edge quality to assess current capabilities.
Obsolescence and Upgrade Potential
Evaluate whether the machine's technology remains relevant for current production needs. Consider the availability of replacement parts and potential upgrade paths for control systems or critical components. Some older used slitting lines offer excellent mechanical foundations for modernization.
Economic Value Assessment
Compare the machine's condition against current market prices for similar equipment. Factor in potential refurbishment costs and expected service life to determine true value. A thorough evaluation helps avoid unexpected expenses after purchase.
By systematically examining these aspects, buyers can make informed decisions about a used slitting line's suitability for their production requirements. Professional inspection services can provide additional assurance when evaluating higher-value equipment.
For more information, please pay attention to the website of Jinyujie Mechanical and Electrical Used Pipe Mill Supplier:www.usedpipemill.com
JinYuJie-Used Pipe Mills Supplier(Please click the link→) :second-hand pipe mill
Assessing the condition of a used slitting line requires a systematic approach to determine its operational capability and remaining service life. Unlike new equipment, pre-owned machines exhibit varying degrees of wear that directly impact performance and value. Below are essential factors to consider when evaluating a used slitting line.
Structural Integrity and Frame Condition
The machine's frame serves as the foundation for precision operations. Inspect for signs of structural fatigue, including cracks, welds, or deformations in the main frame. Check for corrosion, particularly in environments where the used slitting line may have been exposed to moisture or chemicals. A laser alignment test can reveal whether critical components remain properly positioned after years of operation.
Mechanical Wear of Core Components
Examine high-wear components such as shafts, bearings, and gears for excessive play or scoring. The decoiler and recoiler mandrels should be evaluated for straightness and grip strength. On the slitting unit, inspect spindle runout and blade holder conditions. These elements directly affect the machine's ability to maintain tolerances during operation.
Electrical System and Control Reliability
Assess the condition of motors, drives, and control systems. Older used slitting lines may have obsolete electrical components that require upgrading. Test the responsiveness of the PLC or CNC interface and check for consistency in tension control systems. Modernization potential should be considered when evaluating long-term viability.
Hydraulic and Pneumatic Performance
Hydraulic systems in a used slitting line often show signs of leakage or pressure loss. Inspect cylinders, valves, and pumps for proper operation. Pneumatic components should be checked for air leaks and actuator responsiveness. Fluid analysis can reveal contamination levels in hydraulic systems.
Blade Condition and Cutting Accuracy
The slitting knives and associated tooling represent critical wear components. Measure blade sharpness and check for chips or uneven wear patterns. Evaluate the blade adjustment mechanisms for smooth operation and precision. Test cuts on sample material reveal the machine's current cutting capability.
Material Handling System Functionality
Assess the condition of levelers, straighteners, and feed systems. Look for worn rollers, misaligned guides, and tension measurement accuracy. The material handling system significantly impacts the final product quality and operational efficiency of the used slitting line.
Documentation and Service History Review
Request maintenance records and operational logs to understand the machine's service background. Regular servicing and proper lubrication history indicate better-preserved conditions. Verify hours of operation and review any major repairs or component replacements.
Performance Testing Under Load
Conduct trial runs with actual production materials to evaluate the used slitting line under working conditions. Monitor vibration levels, noise patterns, and temperature variations during operation. Measure slit material for dimensional accuracy and edge quality to assess current capabilities.
Obsolescence and Upgrade Potential
Evaluate whether the machine's technology remains relevant for current production needs. Consider the availability of replacement parts and potential upgrade paths for control systems or critical components. Some older used slitting lines offer excellent mechanical foundations for modernization.
Economic Value Assessment
Compare the machine's condition against current market prices for similar equipment. Factor in potential refurbishment costs and expected service life to determine true value. A thorough evaluation helps avoid unexpected expenses after purchase.
By systematically examining these aspects, buyers can make informed decisions about a used slitting line's suitability for their production requirements. Professional inspection services can provide additional assurance when evaluating higher-value equipment.
For more information, please pay attention to the website of Jinyujie Mechanical and Electrical Used Pipe Mill Supplier:www.usedpipemill.com
JinYuJie-Used Pipe Mills Supplier(Please click the link→) :second-hand pipe mill

Time of issue : 2025-07-10
The proper selection and preparation of a production site are critical factors in ensuring optimal performance and safety when operating a used slitting line. Unlike new equipment, second-hand machinery may have specific spatial and environmental needs due to previous usage patterns or wear conditions. Below are key considerations for selecting an appropriate workspace for a used slitting line.
Space Allocation and Layout Planning
Adequate floor space must be allocated to accommodate the entire slitting line, including material storage areas. The layout should allow for smooth coil loading and unloading operations, with sufficient clearance for overhead cranes or forklifts. Since a used slitting line may require more frequent maintenance access, additional space around critical components like the slitter head and tension stations should be incorporated.
Floor Load Capacity and Foundation Requirements
The chosen location must have a reinforced concrete floor capable of supporting the substantial weight of both the machinery and coiled materials. Older slitting lines often have heavier frames compared to modern equivalents, making floor strength assessment crucial. Vibration dampening considerations should be addressed, especially if the equipment shows signs of increased vibration due to wear.
Material Flow Optimization
The workspace should facilitate logical material movement from raw coil storage through processing to finished product staging. For a used slitting line, particular attention should be paid to entry and exit points to prevent material handling bottlenecks. The layout must account for any peculiarities in the machine's feeding or discharge mechanisms that may have developed during its previous service life.
Environmental Conditions Control
Maintaining stable environmental conditions helps preserve the accuracy of a used slitting line. The area should be protected from extreme temperature fluctuations and humidity variations that could affect material properties or machine tolerances. Proper ventilation is essential, especially when processing materials that generate dust or fumes.
Power Supply and Utility Requirements
A used slitting line may have specific electrical needs based on its original configuration and any subsequent modifications. The workspace must provide appropriate power capacity, including voltage stability and phase requirements. Compressed air lines, hydraulic power units, and coolant systems should be positioned for optimal machine performance.
Safety Zones and Emergency Access
Clear safety perimeters must be established around the slitting line, accounting for the machine's age and potential reliability issues. Emergency stop buttons and fire suppression equipment should be easily accessible. The layout should enable quick evacuation routes and provide space for safety barriers where needed.
Lighting and Visibility Considerations
Adequate lighting is particularly important for older equipment where visual inspection of material quality and machine operation is crucial. Task lighting should be positioned to illuminate critical areas such as the slitting zone and tension monitoring points without creating glare or shadows.
Future Expansion and Flexibility
When siting a used slitting line, consideration should be given to potential future upgrades or reconfigurations. The workspace should allow for possible additions of auxiliary equipment or modifications to the material handling system.
Noise Control Measures
Older slitting lines may generate higher noise levels, requiring appropriate acoustic treatment of the workspace. This could include sound-absorbing wall panels or strategic placement of noise barriers between the equipment and operator stations.
By carefully evaluating these factors when selecting a production site, operators can maximize the efficiency and service life of a used slitting line while maintaining a safe working environment. The workspace should be periodically reassessed as the machine's performance characteristics evolve over time.
For more information, please pay attention to the website of Jinyujie Mechanical and Electrical Used Pipe Mill Supplier:www.usedpipemill.com
JinYuJie-Used Pipe Mills Supplier(Please click the link→) :second-hand pipe mill
The proper selection and preparation of a production site are critical factors in ensuring optimal performance and safety when operating a used slitting line. Unlike new equipment, second-hand machinery may have specific spatial and environmental needs due to previous usage patterns or wear conditions. Below are key considerations for selecting an appropriate workspace for a used slitting line.
Space Allocation and Layout Planning
Adequate floor space must be allocated to accommodate the entire slitting line, including material storage areas. The layout should allow for smooth coil loading and unloading operations, with sufficient clearance for overhead cranes or forklifts. Since a used slitting line may require more frequent maintenance access, additional space around critical components like the slitter head and tension stations should be incorporated.
Floor Load Capacity and Foundation Requirements
The chosen location must have a reinforced concrete floor capable of supporting the substantial weight of both the machinery and coiled materials. Older slitting lines often have heavier frames compared to modern equivalents, making floor strength assessment crucial. Vibration dampening considerations should be addressed, especially if the equipment shows signs of increased vibration due to wear.
Material Flow Optimization
The workspace should facilitate logical material movement from raw coil storage through processing to finished product staging. For a used slitting line, particular attention should be paid to entry and exit points to prevent material handling bottlenecks. The layout must account for any peculiarities in the machine's feeding or discharge mechanisms that may have developed during its previous service life.
Environmental Conditions Control
Maintaining stable environmental conditions helps preserve the accuracy of a used slitting line. The area should be protected from extreme temperature fluctuations and humidity variations that could affect material properties or machine tolerances. Proper ventilation is essential, especially when processing materials that generate dust or fumes.
Power Supply and Utility Requirements
A used slitting line may have specific electrical needs based on its original configuration and any subsequent modifications. The workspace must provide appropriate power capacity, including voltage stability and phase requirements. Compressed air lines, hydraulic power units, and coolant systems should be positioned for optimal machine performance.
Safety Zones and Emergency Access
Clear safety perimeters must be established around the slitting line, accounting for the machine's age and potential reliability issues. Emergency stop buttons and fire suppression equipment should be easily accessible. The layout should enable quick evacuation routes and provide space for safety barriers where needed.
Lighting and Visibility Considerations
Adequate lighting is particularly important for older equipment where visual inspection of material quality and machine operation is crucial. Task lighting should be positioned to illuminate critical areas such as the slitting zone and tension monitoring points without creating glare or shadows.
Future Expansion and Flexibility
When siting a used slitting line, consideration should be given to potential future upgrades or reconfigurations. The workspace should allow for possible additions of auxiliary equipment or modifications to the material handling system.
Noise Control Measures
Older slitting lines may generate higher noise levels, requiring appropriate acoustic treatment of the workspace. This could include sound-absorbing wall panels or strategic placement of noise barriers between the equipment and operator stations.
By carefully evaluating these factors when selecting a production site, operators can maximize the efficiency and service life of a used slitting line while maintaining a safe working environment. The workspace should be periodically reassessed as the machine's performance characteristics evolve over time.
For more information, please pay attention to the website of Jinyujie Mechanical and Electrical Used Pipe Mill Supplier:www.usedpipemill.com
JinYuJie-Used Pipe Mills Supplier(Please click the link→) :second-hand pipe mill

Time of issue : 2025-07-09
Proper training is essential for ensuring safe and efficient operation of a used slitting line. Since second-hand equipment may have unique wear patterns or modifications, operators must be thoroughly trained to handle its specific requirements. Below are key aspects of personnel training for a used slitting line:
Understanding Machine Components and Functions
Operators must familiarize themselves with all parts of the slitting line, including the decoiler, slitter, tension control system, and recoiler. Training should cover the purpose of each component, common wear points, and how to identify signs of malfunction. Since a used slitting line may have undergone previous repairs or adjustments, operators should learn its specific configuration.
Safety Procedures and Emergency Protocols
Safety training is critical when working with a used slitting line. Operators must understand lockout/tagout (LOTO) procedures to prevent accidental startups during maintenance. They should also be trained on emergency stop functions, proper PPE usage, and how to handle material jams safely. Since older machines may lack modern safety features, extra caution is necessary.
Material Handling and Setup
Proper material loading and alignment are crucial for smooth operation. Training should include how to safely mount and center coils on the decoiler, adjust tension controls, and thread material through the slitting line. Operators should learn how to select and install the correct blades for different materials, as improper setup can lead to poor cuts or machine damage.
Blade Maintenance and Adjustment
Since blade wear is a common issue in used slitting lines, operators must be trained in blade inspection, sharpening, and replacement. They should understand how to adjust blade gaps for different material thicknesses and recognize when blades need servicing. Proper handling techniques should be emphasized to prevent injuries.
Troubleshooting Common Issues
Operators should be trained to identify and resolve frequent problems in a used slitting line, such as misaligned material, uneven tension, or blade chatter. Training should include basic diagnostic steps and when to escalate issues to maintenance personnel. Documenting recurring problems can help improve long-term reliability.
Preventive Maintenance Practices
Regular maintenance is key to extending the lifespan of a used slitting line. Operators should learn daily inspection routines, lubrication points, and how to clean critical components. Training should emphasize the importance of reporting unusual noises, vibrations, or performance changes before they lead to major failures.
Quality Control and Inspection
Operators must understand how to check slit material for defects such as burrs, edge waves, or dimensional inaccuracies. Training should include using measuring tools and maintaining consistent quality standards. Since a used slitting line may have slight deviations, operators should know how to compensate for them.
Handover and Shift Communication
In multi-shift operations, clear communication is vital. Operators should be trained in proper handover procedures, including reporting machine status, ongoing issues, and maintenance needs. This ensures smooth transitions and reduces downtime.
By implementing comprehensive training programs, companies can maximize the efficiency and safety of a used slitting line, reducing operational risks and improving productivity. Regular refresher courses should be conducted to keep skills updated.
For more information, please pay attention to the website of Jinyujie Mechanical and Electrical Used Pipe Mill Supplier:www.usedpipemill.com
JinYuJie-Used Pipe Mills Supplier(Please click the link→) :second-hand pipe mill
Proper training is essential for ensuring safe and efficient operation of a used slitting line. Since second-hand equipment may have unique wear patterns or modifications, operators must be thoroughly trained to handle its specific requirements. Below are key aspects of personnel training for a used slitting line:
Understanding Machine Components and Functions
Operators must familiarize themselves with all parts of the slitting line, including the decoiler, slitter, tension control system, and recoiler. Training should cover the purpose of each component, common wear points, and how to identify signs of malfunction. Since a used slitting line may have undergone previous repairs or adjustments, operators should learn its specific configuration.
Safety Procedures and Emergency Protocols
Safety training is critical when working with a used slitting line. Operators must understand lockout/tagout (LOTO) procedures to prevent accidental startups during maintenance. They should also be trained on emergency stop functions, proper PPE usage, and how to handle material jams safely. Since older machines may lack modern safety features, extra caution is necessary.
Material Handling and Setup
Proper material loading and alignment are crucial for smooth operation. Training should include how to safely mount and center coils on the decoiler, adjust tension controls, and thread material through the slitting line. Operators should learn how to select and install the correct blades for different materials, as improper setup can lead to poor cuts or machine damage.
Blade Maintenance and Adjustment
Since blade wear is a common issue in used slitting lines, operators must be trained in blade inspection, sharpening, and replacement. They should understand how to adjust blade gaps for different material thicknesses and recognize when blades need servicing. Proper handling techniques should be emphasized to prevent injuries.
Troubleshooting Common Issues
Operators should be trained to identify and resolve frequent problems in a used slitting line, such as misaligned material, uneven tension, or blade chatter. Training should include basic diagnostic steps and when to escalate issues to maintenance personnel. Documenting recurring problems can help improve long-term reliability.
Preventive Maintenance Practices
Regular maintenance is key to extending the lifespan of a used slitting line. Operators should learn daily inspection routines, lubrication points, and how to clean critical components. Training should emphasize the importance of reporting unusual noises, vibrations, or performance changes before they lead to major failures.
Quality Control and Inspection
Operators must understand how to check slit material for defects such as burrs, edge waves, or dimensional inaccuracies. Training should include using measuring tools and maintaining consistent quality standards. Since a used slitting line may have slight deviations, operators should know how to compensate for them.
Handover and Shift Communication
In multi-shift operations, clear communication is vital. Operators should be trained in proper handover procedures, including reporting machine status, ongoing issues, and maintenance needs. This ensures smooth transitions and reduces downtime.
By implementing comprehensive training programs, companies can maximize the efficiency and safety of a used slitting line, reducing operational risks and improving productivity. Regular refresher courses should be conducted to keep skills updated.
For more information, please pay attention to the website of Jinyujie Mechanical and Electrical Used Pipe Mill Supplier:www.usedpipemill.com
JinYuJie-Used Pipe Mills Supplier(Please click the link→) :second-hand pipe mill
Wechat: 13392281699
Email: zty@usedpipemill.com
Company address:No. A99, East Lecong Avenue, Lecong Town, Foshan City, Guangdong Province
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