Ultrasonic flaw detection standard of straight seam steel pipe

In the realm of non-destructive testing for ultrasonic welding of straight seam steel pipes, several methods are typically employed: ultrasonic flaw detection, X-ray inspection, and film inspection. The choice of flaw detection technique can vary, encompassing single-sided double-sided flaw detection, double-sided double-side flaw detection, and single-sided single-side flaw detection. The selection of the appropriate method is contingent upon the wall thickness of the LSAW steel pipe and the breadth of the weld seam. For instances where the weld seam is both thick and broad, single-sided double-side flaw detection or double-sided double-side flaw detection is recommended.

Inspection Standards for LSAW Steel Pipes:

- GB11345-89 and GB/T11345-2013:

These standards guide the non-destructive inspection of flaw detection, with primary and secondary inspections. For structural piping with lower requirements, a three-level inspection is selected.

- Post-Production Testing:

Upon completion of the welded steel pipe, it must undergo mechanical performance tests, flattening tests, and flare tests. Additionally, a pressure-bearing test is conducted at 2.5Mpa within the steel pipe, ensuring no leakage for a minimum of one minute.

- Alternative Testing Method:

The eddy current flaw detection method can be utilized as an alternative to the hydraulic pressure test. This method involves fixing a probe on a frame and maintaining a distance of 3 to 5 mm between the probe and the weld seam. The steel pipe is then comprehensively scanned as it moves rapidly, allowing for a thorough inspection of the weld seam.

This revised standard aims to enhance the clarity and specificity of the inspection process, ensuring the integrity and safety of LSAW steel pipes through rigorous testing protocols.