2 small issues with the pressure vessel
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1. Can magnetic particle testing be performed on Class D welds where fittings with a nominal diameter of less than 76 mm are welded to the shell? 2. The standards specify that fittings with a nominal diameter of less than 250 mm are considered primary pressure-bearing components. If they are thick-walled forgings (without reinforcement rings, reinforced by the wall thickness) and not part of standard pipe specifications, then what dimension should be used to determine them as primary pressure-bearing elements?
First question: I’m not involved in flaw detection, but I think it’s possible to do it; it’s just a matter of the size of the probe； Second question: Is it determined by the nominal diameter whether it is a primarily compressive member (the pipe reinforced with thick-walled forgings also has a nominal size).
First question: According to section 47013 on magnetic particle testing, the minimum magnetic separation distance required for magnetic particle testing applies; penetrant testing is suitable for pipes with a diameter of 76 or less, but magnetic particle testing cannot be used in such cases. Second question: According to the code for fixed capacity, pipes and flanges with a nominal diameter of 250 mm or more are considered the main pressure-bearing elements
I agree with the comments above; in particular, the connections and flanges with a DN of 250 or more are the main pressure-bearing components of the container. For details, refer to the fundamental standard, the ‘Code for Pressure Vessels’. If the original poster doesn’t even know this, then there’s not much more I can say.
I agree with the comments above; in particular, the connections and flanges with a DN of 250 or more are the main pressure-bearing components of the container. For details, refer to the fundamental standard, the ‘Code for Pressure Vessels’. If the original poster doesn’t even know this, then there’s not much more I can say.
When discussing the nominal diameter, it is first necessary to determine the location at which the limits of this diameter are indicated, such as the inner diameter, outer diameter, or average mean diameter. Only after this is clear can the nominal diameter be determined. Section 3.1 of the standards specifies that for coiled or forged cylinders, the inner diameter is used as the nominal diameter of shell-and-tube heat exchangers; for pipe-shaped cylinders, the outer diameter serves as the nominal diameter. For kettle-type reboilers, either the inner or outer diameter of the tube box is used as the nominal diameter of such reboilers
1. The contact method and yoke method can be used to detect transverse defects in Class D welds formed by the welding of nozzles to housings with a nominal diameter of less than 76 mm; they cannot detect circumferential defects； 2. Even thick-walled forged fittings are primarily compression members with a nominal diameter of 250 mm or more.
One more small question: 3. For pressure vessel main materials, PMI testing is required; what size of material is needed for sheets, and what size for forgings?