Testing for catheters smaller than 250 mm
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The drawing only specifies the inspection requirements for the AB weld, RT 20%. The inspection requirements for fittings smaller than 250 mm have not been specified; please share your approaches. 1. Inspect at 20% RT. 2. Change to surface inspection. 3. No detection.
In the case of a wafer-type butt weld flange, the weld between the pipe fitting and the flange is classified as a Class B weld, and RT 20% inspection is also required. The fillet welds at the joint points need to be evaluated on a case-by-case basis to determine whether PT/MT testing is required.
The requirement of GB150 is that the inspection requirements for nozzles smaller than 250 mm shall be specified by the design. Strictly speaking, if the design drawings do not specify it, then no testing is carried out. The introduction of this testing requirement should be the responsibility of the design team. However, if the manufacturing unit raises this issue with the design team, a typical design team will respond by stating that the inspection requirements should follow those for Class A and Class B welds; therefore, a certain strategy is needed when raising such an issue.
Generally, a full mouth examination is carried out – it’s not worth saving on this money
The drawing only specifies the inspection requirements for the AB weld, RT 20%. No inspection requirements for fittings smaller than 250 mm are specified. According to GB150, the inspection requirements for nozzles smaller than 250 mm are specified in the design documents. Since the design documents do not specify any inspection requirements for fittings smaller than 250 mm, the RT20% requirement applicable to Class AB welds shall be followed ； It is equivalent to specifying that RT20% is required for all Class AB welds
Since it’s 20% RT. Are the CD category testing requirements specified in the document? It also does not specify the testing standards for pipe fittings smaller than 250 mm, indicating that such containers are not important. Is it possible to omit the weld inspection for butt joints that are less than 250 mm?
If the drawings do not specify butt joints for DN＜250mm, then carry out 20% RT as per the drawings.
Current standards require designers to take into account an increasing number of factors, and they demand that drawings be detailed and precise.
In general design drawings, when the welding coefficient is set at 1.0, pipe fittings with a diameter of less than 250 mm need to be specified separately; surface inspection shall be carried out in accordance with NB/T47013-2015, and those that meet Grade I standards are acceptable. Of course, you can also raise your requirements. For pipe fittings with a diameter of less than 250 mm, surface inspection is carried out in accordance with NB/T47013-2015, and those that meet Grade I standards are considered acceptable. These are my personal opinions. But for our inspection work, everything has to be written down.