Flange weld inspection

The pipe seat weld (also known as the weld between the pipe and the tube sheet) refers to the welded area where the pipe is connected to the tube sheet. Radiographic testing (RT) is a non-destructive testing (NDT) method widely used to inspect weld quality and internal defects. Radiographic inspection of the pipe seat welds presents certain technical challenges, as the tube sheet is usually thick, and the installation of the pipes can introduce geometric constraints that further complicate the process of radiographic inspection. Theoretically, the pipe socket weld can be subjected to 100% radiographic inspection, but in practice this may require a special radiation source configuration, shooting from multiple angles, or the use of special exposure techniques. For example: 1. Use appropriate irradiation techniques: For instance, elliptical welds may require an elliptical irradiation technique to ensure that the weld area is evenly irradiated. 2. Use different shooting angles: It may be necessary to take photos of the weld from multiple angles in order to cover the entire weld area. 3. Use digital radiography: Digital detectors (such as digital detector arrays, DDA) can be used to improve image quality and reduce exposure time. 4. Use of computed tomography (CT): CT can provide three-dimensional images, making it an effective method for detecting welds with complex geometric structures; however, it is costly and slow. 5. Use of a small-focus X-ray tube and special light guidance technology: In tube sheet inspection, the use of a small-focus X-ray tube along with special light guidance technology helps to improve image quality. When performing 100% radiographic inspection, factors such as inspection standards, acceptance criteria, the actual capabilities of the equipment, the geometric shape of the workpiece, and its material must be taken into account. In practical applications, other non-destructive testing methods such as ultrasonic testing (UT), magnetic particle testing (MT), or penetrant testing (PT) may be used in combination to achieve a comprehensive assessment of the integrity of welds. Before carrying out any NDT tasks, it is necessary to have them evaluated and planned by professionals in order to determine the most suitable testing methods and approaches. .

Magnetic particle or penetrant testing is generally used.

Firstly, from the perspective of standard specifications, welds on branch pipe supports smaller than DN100 do not require radiographic inspection； Secondly, if radiographic inspection is necessary, generally speaking, the film cannot be placed inside the pipeline; it can only be attached to the outside of the corner joints. The radiation source, on the other hand, must be positioned at an appropriate angle on the other side of the main pipe in order to obtain a view through both walls. I think this might be possible in theory, but in practice it may not be feasible. These are personal opinions for reference only.

The study faction, huh. Practitioners say that when applying the weld patch, there are gaps in the middle, preventing it from being attached properly. Cannot be exposed.

Radiographic testing is feasible; it is specified in NB/T47013.2. In the case of power pipelines, in addition to surface non-destructive testing, internal non-destructive testing is also required.

If rays don’t work, use a phased array; it can also be used to create recordings

I would like to ask: for the welds connecting branch pipes of this specification, internal inspections are required. Which standard governs this requirement? Thank you

Take a look at GB150; a few days ago, when I wasn’t sure which standard to refer to, I came across information regarding this type of weld, which also requires radiographic or ultrasonic non-destructive testing.

Your T-joint essentially forms something similar to a ring weld