It is difficult to control the wall thickness of straight seam steel pipe. At present, the methods to improve the wall thickness accuracy of black jacket direct buried straight seam steel pipe manufacturers are generally as follows:

　　1. The pipe will be heated

　　The heat is heated to an average level to prevent temperature fluctuations. When the takeoff and landing temperatures are stable, the maximum lifting temperature shall not exceed 30 ℃.

　　2. Mill spindle

　　The average wall thickness of thick walled tube and solid billet significantly reduces the possibility of mandrel bending deformation and can effectively improve the accuracy of wall thickness.

　　3. Spindle accuracy

　　The machining accuracy shall be controlled within 0.1mm ± outer core, and the straightness deviation of mandrel shall not exceed 5mm. During the welding process, a sizing pin is placed between the two mandrels to avoid the deviation of the welding bus lead.

　　4. Perfect technology

　　Determine whether the straightening roll device is in place, adjust the corresponding core roll in the middle, open the same opening angle and size, and pass through the middle of the rolling core on the rolling line.

　　5. Adjustment volume

　　The perfect technology is to avoid the center thinning and the wall thickness exceeding the state control limit, and to improve the wall thickness accuracy.

　　6. Perforated mandrel

　　Generally, the punch diameter is Φ 108 mm - 114 mm Φ, and the thickness of 25 mm or higher is required. Thick wall pipe wall thickness is common.

　　7. Scroll middle row

　　Ensure that the center line of punch is consistent with the center line of the trolley with holes to prevent "up rolling" or "down rolling", so that the rough is affected by the average force during the processing. Puncture process.

　　8. Rolling items

　　The wear of head, guide rail, roller and other rolling objects shall change in real time.

　　9. Roller

　　The rolling distance must be in the middle of the rolling line. During drilling and rolling, ensure that the distance between the guide roll and the roll is equal to the distance between the upper roll and the lower roll.

　　The above is the relevant content introduced by the manufacturer of black jacket direct buried straight seam steel pipe. For more information, please visit the website: https://www.sdhpgy.com