Tube Mill Production Process Flow(I)

The high-frequency straight seam welded pipe production line is also known as the tube mill production line.

The main production processes are as follows：

I. Preparatory Feeding Process

1. Firstly, inspect the appearance dimensions of the steel coil to ensure compliance with the production process card requirements. Report promptly to the shift leader for any issues. When inspecting the quality of the steel coil, personnel should stand at the side to prevent accidents such as coil tipping or uncoupling hitting people.

2. After selecting the steel strip, instruct the overhead crane operator to lower the steel strip vertically onto the feeding trolley and adjust it. When hoisting the steel strip, use gestures and verbal commands simultaneously, ensuring the hook is securely fastened to prevent accidents such as collisions or crushing.

3. After the steel coil is placed correctly, evenly open two mandrels, leaving enough space between them for the steel coil.

4. Move the feeding trolley forward until the center of the steel strip aligns with the center of the two mandrels.

5. Start the hydraulic lifting device to roughly align the center of the steel coil with the center of the mandrels and on the rolling centerline.

6. Evenly retract the two mandrels to snugly hold the steel coil against their inclined surfaces.

7. After the mandrels support the steel coil, lower the hydraulic device and simultaneously withdraw the feeding trolley for the next coil loading.

8. For rolling mills without feeding trolleys, instruct the crane operator to safely place the steel strip into the tightened uncoiler tensioning device.

II. Preparatory Shearing and Butt Welding Process

1. Start the tensioning device hydraulic switch to tension the inner coil of the steel strip.

2. Lower the pressure roller and remove the coil packaging strap with clamping tools. Then open the shovel to the horizontal position and start the uncoiler motor to bring the leading end to the shovel plane.

3. Rotate the uncoiler motor in the specified direction to continue moving the leading end on the shovel plane until reaching the flattening machine.

4. Start the flattening machine motor to continue advancing the steel strip until the hydraulic shear, then stop the uncoiler motor.

5. Open the hydraulic shear and cut the leading end without waste. Then raise the hydraulic shear.

6. Restart the flattening and feeding motor to feed the steel strip to the welding area.

7. After trimming the trailing end of the previous coil and aligning it with the leading end of the new coil, adjust the welding parameters (including welding current, arc voltage, and carbon dioxide flow) and weld the steel strip.

8. The welded joint should have a flat, slag-free, and strong appearance, with a weld seam height not exceeding 1mm.

9. After welding the joint, lift the pressing device, then start the feeding roller motor to feed the welded steel strip into the horizontal spiral mandrel.

III. Tube Mill Rolling Process

1. Before starting the machine, check whether there are any people or objects affecting normal production in front and rear of the mainframe and coordinate with the preceding and subsequent processes.

2. Start the power supply and check if the circuit system is intact, and if all production parameters comply with the production process requirements.

3. Use an electric bell to remind the mainframe staff to take their positions and prepare for production.

4. Before starting the rolling mill, first start the rolling mill pump. After the cooling water indicator light is on, upon receiving the adjustment command, start the transmission motor.

5. As the speed increases, the power also increases correspondingly until both meet the requirements of the welding production process.

6. For steel pipes requiring intermediate frequency annealing, start the intermediate frequency after the welded pipe meets the production process requirements, and ensure the annealing temperature reaches the process requirements.

7. In case of emergencies, the operator should stop the machine by pressing the emergency stop button.

IV. Flying Saw Process

1. Before starting the flying saw machine, comprehensively check if all systems are functioning properly. Report any anomalies to relevant authorities immediately.

2. Conduct a dry run of the saw carriage to ensure it operates smoothly and meets production requirements. Notify the mill operator when it is ready for operation.

3. When cutting grooves, welds, or poorly welded steel pipes manually, the operator should quickly calculate the cutting length to minimize material wastage.

4. When inspecting the inner and outer surface quality of the steel pipe, wait until the saw blade is raised before approaching the steel pipe for observation. Alternatively, manually check the welded seam inside the steel pipe, avoiding bending down to visually inspect.

5. If there are burrs inside or outside the steel pipe that are not properly removed, promptly report to the mill adjustment personnel and stop the machine for rectification.