Questions regarding the prerequisites for inspecting the butt welds between long-neck flanges and cylinders
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According to 6.6.1.2 of NB/T47020, for long-neck flanges, when the operating pressure is greater than or equal to 0.8 times the maximum allowable operating pressure specified in this standard, the butt weld between the flange and the cylinder must undergo 100% radiographic or ultrasonic testing. Taking the example shown in the diagram, as required above, is it necessary to conduct 100% radiographic or ultrasonic testing on the butt weld between the flange and the cylinder?
What pressure rating flange should be selected?
This post was last edited by KASSEM on 2020-9-24 at 13:41: flange pressure 4.0Mpa, material 16Mn Ⅱ
340 degrees is not low. Let’s do a 100% radiation scan!
To meet the design requirements: 2.93 MPa + 340°C!
This post was last edited by wanlirn on 2020-9-24 at 14:47. I’m not sure what material your flanges are made of; could you give an example? For instance, if you use standard flanges with a pressure rating of 4.0 MPa, you would look up the maximum allowable operating pressure at your working temperature, which is 3.0 MPa. If the operating pressure indicated in your diagram is 2.6 MPa, this is higher than the maximum allowable value of 3.0 MPa; therefore, 100% RT testing is necessary.
In other words, is it to compare the maximum allowable operating pressure of the flange at the design temperature with 80 percent of the design pressure?
What you’re referring to here are the mandatory requirements for selecting flanges, which is not the same as what the original poster asked about
I used to understand it the same way, but after seeing a diagram from a certain complex, it stated that…
This post was last edited by wanlirn on 2020-9-24 at 15:07. It’s no big deal – there’s no need to make a fuss about it. The design institute can certainly set higher standards. He believes that this equipment is quite important