Seamless steel pipe size out of tolerance

Seamless steel pipe size out of tolerance is a problem that may be encountered during production and use. It may be caused by a variety of factors and affect the performance and use of steel pipes.

Main types of seamless steel pipe size out of tolerance

1. Uneven wall thickness: The wall thickness of the steel pipe is uneven on the same cross section, which may be caused by uneven heating of the tube billet, unadjusted rolling line of the punching machine, and other factors.

2. Wall thickness out of tolerance: The wall thickness of the steel pipe exceeds the tolerance in one direction, which may also be related to factors such as uneven heating of the tube billet and improper adjustment of the punching machine.

3. Outer diameter out of tolerance: The outer diameter of the steel pipe exceeds the standard. Common reasons include excessive wear of the hole type of the sizing machine.

4. Bending: The seamless steel pipe is not straight along the length direction or has a goose-head-shaped bend at the end of the steel pipe. It may be caused by local water cooling during manual heat inspection.

5. Length out of tolerance: The length of the seamless steel pipe exceeds the requirement, which may be related to factors such as the length of the tube billet exceeding the standard.

Impact of over-tolerance of seamless steel pipe size

1. Performance impact: Seamless steel pipes with over-tolerance may be affected in performance. For example, uneven wall thickness or over-tolerance may affect the bearing capacity, pressure resistance and wear resistance of the steel pipe; over-tolerance of outer diameter may cause oil leakage, air leakage and other problems during use; bending may affect the straightness and installation accuracy of the steel pipe.

2. Use effect: Seamless steel pipes with over-tolerance may not meet the design requirements during use, resulting in a decline in project quality or safety hazards.