I have a few questions regarding pipe fittings flanges, specifically about pound ratings and wall thickness
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In many inquiries, the specifications for fittings and flanges are not exactly the same; for example, between \"90-degree elbow 1.5D SHC 40 A234 WPB\" and \"90-degree elbow 1.5D 150# A234 WPB\", which one is incorrect, or are both correct? If it’s the correct correspondence between wall thickness and weight class, can that be found there? The same is true for flanges, except for WN flanges. Please help! ! !
Both are fine; they just use different ways of representation. 1.5D indicates its radius of curvature, SCH40 denotes its wall thickness grade, and A234 is the standard designation for pipes and fittings. 150 pounds = 1.0 MPA = 10 kilograms of pressure
What is provided to the pipe fitting factory should clearly indicate the pipe thickness or SCH value. So 90-degree elbow, 1.5D, 150# A234 WPB is incorrect. Providing only the weight class is not sufficient; pipe fitting manufacturers need to calculate the actual wall thickness, and to do so they require parameters such as design pressure, design temperature, and corrosion allowance. This results in a mismatch between the actual materials used for the fittings and pipelines; this is acceptable under normal circumstances, but if there are significant deviations in the design parameters, serious misalignments will occur, and such misalignments will affect the results of radiographic inspections. Therefore, it is not recommended to use pounds as a unit of measurement.
90-degree elbow, 1.5D SHC 40 A234 WPB – this is correct. SCH40 is the wall thickness grade for the elbow, while A234 WPB is the material code for the elbow. In the designation 1.5D 150# A234 WPB, 150# is not the correct value to indicate the wall thickness of the elbow; 150# is generally used to denote the pressure rating of valves, flanges, etc. There is no established correspondence between wall thickness and pressure ratings.