What should be paid attention to in pipeline welding and flaw detection

Unless otherwise specified in the design documents, X-rays shall be used for nondestructive testing of welded joints of pipelines, and ultrasonic waves shall be used for welds with thickness less than or equal to 30 mm The inspection quantity and acceptance criteria shall meet the provisions in Table 9.3. 1 and the following requirements:

1, the technical level of X-ray inspection should be AB;

2. The technical level of ultrasonic testing shall be Grade B. ..

Inspection method: check the pipeline single line diagram and nondestructive testing report.

GC 1 pipeline, pipeline with design temperature lower than or equal to -20℃, alloy steel pipeline with greater hardening tendency, stainless steel pipeline and non-ferrous metal pipeline shall be welded by argon arc welding, and the surface shall not be scratched by arc.

Non-destructive flaw detection of pipeline welds is to project welds with rays, and then reflect the weld situation after exposure through negative film. Non-destructive testing includes X-ray perspective, ultrasonic testing, magnetic particle testing, coloring testing, V-ray testing and penetrant testing.

Extended data

There is no specific regulation on the first pass rate of pipeline welding film, and the first pass rate of film only reflects the construction technology level and management level of construction enterprises. In our company's quality goal, the first pass rate of welding pieces is set at more than 95%, and the target decomposition should be carried out according to the actual construction situation in the project. Materials with good weldability, good welding environment, and pipeline prefabrication welding (re-export welding) can be set at a higher level, otherwise they can be set at a lower level, but the overall level should reach more than 95%.

To improve the first pass rate of welding pieces, I think we should control it from five factors: people, machines, materials, methods and environment. Person: According to the welder examination rules, you must hold a certificate and have the corresponding welding qualification items. If necessary, take the skills test for the first time, and then go to work after passing the exam (this is generally the case for foreign-funded projects).

Baidu encyclopedia-radiographic inspection